diff --git a/frontend/app/player/MessageDistributor/MessageDistributor.ts b/frontend/app/player/MessageDistributor/MessageDistributor.ts
index 1abd26979..456dcb6dd 100644
--- a/frontend/app/player/MessageDistributor/MessageDistributor.ts
+++ b/frontend/app/player/MessageDistributor/MessageDistributor.ts
@@ -147,7 +147,7 @@ export default class MessageDistributor extends StatedScreen {
 
         // @ts-ignore Hack for upet (TODO: fix ordering in one mutation in tracker(removes first))
         const headChildrenIds = msgs.filter(m => m.parentID === 1).map(m => m.id);
-        this.pagesManager.sort((m1, m2) => {
+        this.pagesManager.sortPages((m1, m2) => {
           if (m1.time === m2.time) {
             if (m1.tp === "remove_node" && m2.tp !== "remove_node") {
               if (headChildrenIds.includes(m1.id)) {
diff --git a/frontend/app/player/MessageDistributor/StatedScreen/Screen/Cursor.ts b/frontend/app/player/MessageDistributor/StatedScreen/Screen/Cursor.ts
index ee527677b..cd583c05b 100644
--- a/frontend/app/player/MessageDistributor/StatedScreen/Screen/Cursor.ts
+++ b/frontend/app/player/MessageDistributor/StatedScreen/Screen/Cursor.ts
@@ -33,6 +33,10 @@ export default class Cursor {
     }, 600)
   }
 
+  // TODO (to keep on a different playig speed):
+  // transition
+  // setTransitionSpeed()
+
   getPosition(): Point {
     return { x: this.position.x, y: this.position.y };
   }
diff --git a/frontend/app/player/MessageDistributor/managers/ListWalker.ts b/frontend/app/player/MessageDistributor/managers/ListWalker.ts
index 63f549338..9bae8203e 100644
--- a/frontend/app/player/MessageDistributor/managers/ListWalker.ts
+++ b/frontend/app/player/MessageDistributor/managers/ListWalker.ts
@@ -16,12 +16,12 @@ export default class ListWalker<T extends Timed> {
 		this.p = 0
 	}
 
-	sort(comparator): void {
+	sort(comparator: (a: T, b: T) => number): void {
 		// @ts-ignore
 		this._list.sort((m1,m2) => comparator(m1,m2) || (m1._index - m2._index) ); // indexes for sort stability (TODO: fix types???)
 	}
 
-	forEach(f):void {
+	forEach(f: (item: T) => void):void {
 		this._list.forEach(f);
 	}
 
diff --git a/frontend/app/player/MessageDistributor/managers/PagesManager.ts b/frontend/app/player/MessageDistributor/managers/PagesManager.ts
index 7c6095b1e..0a463fe97 100644
--- a/frontend/app/player/MessageDistributor/managers/PagesManager.ts
+++ b/frontend/app/player/MessageDistributor/managers/PagesManager.ts
@@ -31,7 +31,7 @@ export default class PagesManager extends ListWalker<DOMManager> {
 		this.last.append(m)
 	}
 
-	sort(comparator) {
+	sortPages(comparator: (a: Message, b: Message) => number) {
 		this.forEach(page => page.sort(comparator))
 	}
 
diff --git a/frontend/app/player/MessageDistributor/messages/RawMessageReader.ts b/frontend/app/player/MessageDistributor/messages/RawMessageReader.ts
index 867d80755..501a85a7b 100644
--- a/frontend/app/player/MessageDistributor/messages/RawMessageReader.ts
+++ b/frontend/app/player/MessageDistributor/messages/RawMessageReader.ts
@@ -751,7 +751,7 @@ export default class RawMessageReader extends PrimitiveReader {
     }
     
     default:
-      throw new Error(`Unrecognizable message type: ${ tp }`)
+      throw new Error(`Unrecognizable message type: ${ tp }; Pointer at the position ${this.p} of ${this.buf.length}`)
       return null;
     }
   }