Resolve #814

app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/PageLoader.kt

@@ -61,8 +61,8 @@ abstract class PageLoader {
 
     protected abstract fun onForceRequest(index: Int)
 
-    fun cancelRequest(index: Int) {
-        onCancelRequest(index)
+    fun cancelRequest(page: ReaderPage) {
+        onCancelRequest(mPages.indexOf(page))
     }
 
     protected abstract fun onCancelRequest(index: Int)

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/pager/PagerViewerAdapter.kt

@@ -62,7 +62,8 @@ class PagerViewerAdapter(private val viewer: PagerViewer) : ViewPagerAdapter() {
     }
 
     override fun destroyView(container: ViewGroup, position: Int, view: View) {
-        currentChapter?.cancelRequest(position)
+        val item = items[position]
+        currentChapter?.cancelRequest(item as ReaderPage)
     }
 
     /**

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/webtoon/WebtoonAdapter.kt

@@ -84,10 +84,11 @@ class WebtoonAdapter(val viewer: WebtoonViewer) : RecyclerView.Adapter<RecyclerV
      * Recycles an existing view [holder] before adding it to the view pool.
      */
     override fun onViewRecycled(holder: RecyclerView.ViewHolder) {
-        currentChapter?.cancelRequest(holder.bindingAdapterPosition)
         when (holder) {
             is WebtoonPageHolder -> holder.recycle()
         }
+        val item = items.getOrNull(holder.bindingAdapterPosition) ?: return
+        currentChapter?.cancelRequest(item as ReaderPage)
     }
 }