diff --git a/app/src/main/java/com/github/damontecres/wholphin/MainActivity.kt b/app/src/main/java/com/github/damontecres/wholphin/MainActivity.kt
index 6aa749f1..8d9beccb 100644
--- a/app/src/main/java/com/github/damontecres/wholphin/MainActivity.kt
+++ b/app/src/main/java/com/github/damontecres/wholphin/MainActivity.kt
@@ -61,6 +61,7 @@ import com.github.damontecres.wholphin.ui.util.ProvideLocalClock
 import com.github.damontecres.wholphin.util.DebugLogTree
 import com.github.damontecres.wholphin.util.ExceptionHandler
 import com.github.damontecres.wholphin.util.WholphinDispatchers
+import com.github.damontecres.wholphin.util.requestSerializersModule
 import dagger.hilt.android.AndroidEntryPoint
 import dagger.hilt.android.lifecycle.HiltViewModel
 import dagger.hilt.android.qualifiers.ApplicationContext
@@ -141,6 +142,7 @@ class MainActivity : AppCompatActivity() {
     private val json =
         Json {
             classDiscriminator = "_type"
+            serializersModule = requestSerializersModule
         }
 
     @OptIn(ExperimentalTvMaterial3Api::class)
@@ -151,10 +153,22 @@ class MainActivity : AppCompatActivity() {
         lifecycle.addObserver(playbackLifecycleObserver)
 
         val backStackStr = savedInstanceState?.getString(KEY_BACK_STACK)
-        if (backStackStr != null) {
+        val restoredBackStack =
+            if (backStackStr != null) {
+                try {
+                    json.decodeFromString<List<Destination>>(backStackStr)
+                } catch (ex: Exception) {
+                    // Best-effort: a previously persisted back stack we can no longer decode
+                    // must not crash startup; fall back to a fresh start destination.
+                    Timber.w(ex, "Could not restore back stack; starting fresh")
+                    null
+                }
+            } else {
+                null
+            }
+        if (restoredBackStack != null) {
             Timber.d("Restoring back stack")
-            var backStack = json.decodeFromString<List<Destination>>(backStackStr)
-
+            var backStack = restoredBackStack
             if (!playExternalViewModel.launched.value) {
                 val lastDest = backStack.lastOrNull()
                 if (lastDest.isPlayback) {
@@ -320,8 +334,14 @@ class MainActivity : AppCompatActivity() {
     override fun onSaveInstanceState(outState: Bundle) {
         super.onSaveInstanceState(outState)
         Timber.d("onSaveInstanceState")
-        val str = json.encodeToString(navigationManager.backStack.toList())
-        outState.putString(KEY_BACK_STACK, str)
+        try {
+            val str = json.encodeToString(navigationManager.backStack.toList())
+            outState.putString(KEY_BACK_STACK, str)
+        } catch (ex: Exception) {
+            // Best-effort: some destinations carry types we can't serialize; skip persisting
+            // the back stack rather than crashing in onSaveInstanceState.
+            Timber.w(ex, "Could not persist back stack; skipping")
+        }
         val playerBackend =
             runBlocking { userPreferencesDataStore.data.firstOrNull() }?.playbackPreferences?.playerBackend
         outState.putBoolean(KEY_EXTERNAL_PLAYER, playerBackend == PlayerBackend.EXTERNAL_PLAYER)
diff --git a/app/src/main/java/com/github/damontecres/wholphin/util/ApiRequestPager.kt b/app/src/main/java/com/github/damontecres/wholphin/util/ApiRequestPager.kt
index 32b66d04..555a5a51 100644
--- a/app/src/main/java/com/github/damontecres/wholphin/util/ApiRequestPager.kt
+++ b/app/src/main/java/com/github/damontecres/wholphin/util/ApiRequestPager.kt
@@ -5,6 +5,9 @@ import com.github.damontecres.wholphin.ui.DEFAULT_PAGE_SIZE
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.sync.withLock
 import kotlinx.serialization.Serializable
+import kotlinx.serialization.modules.SerializersModule
+import kotlinx.serialization.modules.polymorphic
+import kotlinx.serialization.modules.subclass
 import org.jellyfin.sdk.api.client.ApiClient
 import org.jellyfin.sdk.api.client.Response
 import org.jellyfin.sdk.api.client.extensions.genresApi
@@ -107,7 +110,8 @@ class ApiRequestPager<T>(
 /**
  * Specifies how a [RequestPager] should prepare and execute API calls
  */
-interface RequestHandler<T> {
+@Serializable
+sealed interface RequestHandler<T> {
     /**
      * Prepare the given request with the specified parameters (eg which page to fetch)
      */
@@ -128,245 +132,255 @@ interface RequestHandler<T> {
 }
 
 @Serializable
-val GetItemsRequestHandler =
-    object : RequestHandler<GetItemsRequest> {
-        override fun prepare(
-            request: GetItemsRequest,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetItemsRequest =
-            request.copy(
-                startIndex = startIndex,
-                limit = limit,
-                enableTotalRecordCount = enableTotalRecordCount,
-            )
+object GetItemsRequestHandler : RequestHandler<GetItemsRequest> {
+    override fun prepare(
+        request: GetItemsRequest,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetItemsRequest =
+        request.copy(
+            startIndex = startIndex,
+            limit = limit,
+            enableTotalRecordCount = enableTotalRecordCount,
+        )
 
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetItemsRequest,
-        ): Response<BaseItemDtoQueryResult> = api.itemsApi.getItems(request)
-    }
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetItemsRequest,
+    ): Response<BaseItemDtoQueryResult> = api.itemsApi.getItems(request)
+}
 
 @Serializable
-val GetEpisodesRequestHandler =
-    object : RequestHandler<GetEpisodesRequest> {
-        override fun prepare(
-            request: GetEpisodesRequest,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetEpisodesRequest =
-            request.copy(
-                startIndex = startIndex,
-                limit = limit,
-            )
+object GetEpisodesRequestHandler : RequestHandler<GetEpisodesRequest> {
+    override fun prepare(
+        request: GetEpisodesRequest,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetEpisodesRequest =
+        request.copy(
+            startIndex = startIndex,
+            limit = limit,
+        )
 
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetEpisodesRequest,
-        ): Response<BaseItemDtoQueryResult> = api.tvShowsApi.getEpisodes(request)
-    }
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetEpisodesRequest,
+    ): Response<BaseItemDtoQueryResult> = api.tvShowsApi.getEpisodes(request)
+}
 
 @Serializable
-val GetResumeItemsRequestHandler =
-    object : RequestHandler<GetResumeItemsRequest> {
-        override fun prepare(
-            request: GetResumeItemsRequest,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetResumeItemsRequest =
-            request.copy(
-                startIndex = startIndex,
-                limit = limit,
-                enableTotalRecordCount = enableTotalRecordCount,
-            )
+object GetResumeItemsRequestHandler : RequestHandler<GetResumeItemsRequest> {
+    override fun prepare(
+        request: GetResumeItemsRequest,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetResumeItemsRequest =
+        request.copy(
+            startIndex = startIndex,
+            limit = limit,
+            enableTotalRecordCount = enableTotalRecordCount,
+        )
 
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetResumeItemsRequest,
-        ): Response<BaseItemDtoQueryResult> = api.itemsApi.getResumeItems(request)
-    }
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetResumeItemsRequest,
+    ): Response<BaseItemDtoQueryResult> = api.itemsApi.getResumeItems(request)
+}
 
 @Serializable
-val GetNextUpRequestHandler =
-    object : RequestHandler<GetNextUpRequest> {
-        override fun prepare(
-            request: GetNextUpRequest,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetNextUpRequest =
-            request.copy(
-                startIndex = startIndex,
-                limit = limit,
-                enableTotalRecordCount = enableTotalRecordCount,
-            )
+object GetNextUpRequestHandler : RequestHandler<GetNextUpRequest> {
+    override fun prepare(
+        request: GetNextUpRequest,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetNextUpRequest =
+        request.copy(
+            startIndex = startIndex,
+            limit = limit,
+            enableTotalRecordCount = enableTotalRecordCount,
+        )
 
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetNextUpRequest,
-        ): Response<BaseItemDtoQueryResult> = api.tvShowsApi.getNextUp(request)
-    }
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetNextUpRequest,
+    ): Response<BaseItemDtoQueryResult> = api.tvShowsApi.getNextUp(request)
+}
 
 @Serializable
-val GetSuggestionsRequestHandler =
-    object : RequestHandler<GetSuggestionsRequest> {
-        override fun prepare(
-            request: GetSuggestionsRequest,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetSuggestionsRequest =
-            request.copy(
-                startIndex = startIndex,
-                limit = limit,
-                enableTotalRecordCount = enableTotalRecordCount,
-            )
+object GetSuggestionsRequestHandler : RequestHandler<GetSuggestionsRequest> {
+    override fun prepare(
+        request: GetSuggestionsRequest,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetSuggestionsRequest =
+        request.copy(
+            startIndex = startIndex,
+            limit = limit,
+            enableTotalRecordCount = enableTotalRecordCount,
+        )
 
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetSuggestionsRequest,
-        ): Response<BaseItemDtoQueryResult> = api.suggestionsApi.getSuggestions(request)
-    }
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetSuggestionsRequest,
+    ): Response<BaseItemDtoQueryResult> = api.suggestionsApi.getSuggestions(request)
+}
 
 @Serializable
-val GetPlaylistItemsRequestHandler =
-    object : RequestHandler<GetPlaylistItemsRequest> {
-        override fun prepare(
-            request: GetPlaylistItemsRequest,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetPlaylistItemsRequest =
-            request.copy(
-                startIndex = startIndex,
-                limit = limit,
-            )
+object GetPlaylistItemsRequestHandler : RequestHandler<GetPlaylistItemsRequest> {
+    override fun prepare(
+        request: GetPlaylistItemsRequest,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetPlaylistItemsRequest =
+        request.copy(
+            startIndex = startIndex,
+            limit = limit,
+        )
 
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetPlaylistItemsRequest,
-        ): Response<BaseItemDtoQueryResult> = api.playlistsApi.getPlaylistItems(request)
-    }
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetPlaylistItemsRequest,
+    ): Response<BaseItemDtoQueryResult> = api.playlistsApi.getPlaylistItems(request)
+}
 
 @Serializable
-val GetGenresRequestHandler =
-    object : RequestHandler<GetGenresRequest> {
-        override fun prepare(
-            request: GetGenresRequest,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetGenresRequest =
-            request.copy(
-                startIndex = startIndex,
-                limit = limit,
-                enableTotalRecordCount = enableTotalRecordCount,
-            )
+object GetGenresRequestHandler : RequestHandler<GetGenresRequest> {
+    override fun prepare(
+        request: GetGenresRequest,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetGenresRequest =
+        request.copy(
+            startIndex = startIndex,
+            limit = limit,
+            enableTotalRecordCount = enableTotalRecordCount,
+        )
 
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetGenresRequest,
-        ): Response<BaseItemDtoQueryResult> = api.genresApi.getGenres(request)
-    }
-
-val GetProgramsDtoHandler =
-    object : RequestHandler<GetProgramsDto> {
-        override fun prepare(
-            request: GetProgramsDto,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetProgramsDto =
-            request.copy(
-                startIndex = startIndex,
-                limit = limit,
-            )
-
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetProgramsDto,
-        ): Response<BaseItemDtoQueryResult> = api.liveTvApi.getPrograms(request)
-    }
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetGenresRequest,
+    ): Response<BaseItemDtoQueryResult> = api.genresApi.getGenres(request)
+}
 
 @Serializable
-val GetPersonsHandler =
-    object : RequestHandler<GetPersonsRequest> {
-        override fun prepare(
-            request: GetPersonsRequest,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetPersonsRequest =
-            request.copy(
+object GetProgramsDtoHandler : RequestHandler<GetProgramsDto> {
+    override fun prepare(
+        request: GetProgramsDto,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetProgramsDto =
+        request.copy(
+            startIndex = startIndex,
+            limit = limit,
+        )
+
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetProgramsDto,
+    ): Response<BaseItemDtoQueryResult> = api.liveTvApi.getPrograms(request)
+}
+
+@Serializable
+object GetPersonsHandler : RequestHandler<GetPersonsRequest> {
+    override fun prepare(
+        request: GetPersonsRequest,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetPersonsRequest =
+        request.copy(
 //                startIndex = startIndex,
-                limit = limit,
-            )
+            limit = limit,
+        )
 
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetPersonsRequest,
-        ): Response<BaseItemDtoQueryResult> = api.personsApi.getPersons((request))
-    }
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetPersonsRequest,
+    ): Response<BaseItemDtoQueryResult> = api.personsApi.getPersons((request))
+}
 
-val GetStudiosRequestHandler =
-    object : RequestHandler<GetStudiosRequest> {
-        override fun prepare(
-            request: GetStudiosRequest,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetStudiosRequest =
-            request.copy(
-                startIndex = startIndex,
-                limit = limit,
-                enableTotalRecordCount = enableTotalRecordCount,
-            )
+@Serializable
+object GetStudiosRequestHandler : RequestHandler<GetStudiosRequest> {
+    override fun prepare(
+        request: GetStudiosRequest,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetStudiosRequest =
+        request.copy(
+            startIndex = startIndex,
+            limit = limit,
+            enableTotalRecordCount = enableTotalRecordCount,
+        )
 
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetStudiosRequest,
-        ): Response<BaseItemDtoQueryResult> = api.studiosApi.getStudios(request)
-    }
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetStudiosRequest,
+    ): Response<BaseItemDtoQueryResult> = api.studiosApi.getStudios(request)
+}
 
-val GetRecordingsRequestHandler =
-    object : RequestHandler<GetRecordingsRequest> {
-        override fun prepare(
-            request: GetRecordingsRequest,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetRecordingsRequest =
-            request.copy(
-                startIndex = startIndex,
-                limit = limit,
-                enableTotalRecordCount = enableTotalRecordCount,
-            )
+@Serializable
+object GetRecordingsRequestHandler : RequestHandler<GetRecordingsRequest> {
+    override fun prepare(
+        request: GetRecordingsRequest,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetRecordingsRequest =
+        request.copy(
+            startIndex = startIndex,
+            limit = limit,
+            enableTotalRecordCount = enableTotalRecordCount,
+        )
 
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetRecordingsRequest,
-        ): Response<BaseItemDtoQueryResult> = api.liveTvApi.getRecordings(request)
-    }
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetRecordingsRequest,
+    ): Response<BaseItemDtoQueryResult> = api.liveTvApi.getRecordings(request)
+}
 
-val GetLiveTvChannelsRequestHandler =
-    object : RequestHandler<GetLiveTvChannelsRequest> {
-        override fun prepare(
-            request: GetLiveTvChannelsRequest,
-            startIndex: Int,
-            limit: Int,
-            enableTotalRecordCount: Boolean,
-        ): GetLiveTvChannelsRequest =
-            request.copy(
-                startIndex = startIndex,
-                limit = limit,
+@Serializable
+object GetLiveTvChannelsRequestHandler : RequestHandler<GetLiveTvChannelsRequest> {
+    override fun prepare(
+        request: GetLiveTvChannelsRequest,
+        startIndex: Int,
+        limit: Int,
+        enableTotalRecordCount: Boolean,
+    ): GetLiveTvChannelsRequest =
+        request.copy(
+            startIndex = startIndex,
+            limit = limit,
 //                enableTotalRecordCount = enableTotalRecordCount,
-            )
+        )
 
-        override suspend fun execute(
-            api: ApiClient,
-            request: GetLiveTvChannelsRequest,
-        ): Response<BaseItemDtoQueryResult> = api.liveTvApi.getLiveTvChannels(request)
+    override suspend fun execute(
+        api: ApiClient,
+        request: GetLiveTvChannelsRequest,
+    ): Response<BaseItemDtoQueryResult> = api.liveTvApi.getLiveTvChannels(request)
+}
+
+val requestSerializersModule =
+    SerializersModule {
+        polymorphic(Any::class) {
+            subclass(GetItemsRequest::class)
+            subclass(GetEpisodesRequest::class)
+            subclass(GetResumeItemsRequest::class)
+            subclass(GetNextUpRequest::class)
+            subclass(GetSuggestionsRequest::class)
+            subclass(GetPlaylistItemsRequest::class)
+            subclass(GetGenresRequest::class)
+            subclass(GetProgramsDto::class)
+            subclass(GetPersonsRequest::class)
+            subclass(GetStudiosRequest::class)
+            subclass(GetRecordingsRequest::class)
+            subclass(GetLiveTvChannelsRequest::class)
+        }
     }