Application crashes when deleting bookmark

Project Information

Repository Link
https://github.com/lfuelling/lrkFM

Expected Behavior

After adding a bookmark, i trying delete it again. I hope the bookmark is erased, and yeah it can be deleted

Actual Behavior

Which actually happens here, after I add the bookmark and delete it again, the application crashes.

How To Reproduce

• Download https://play.google.com/store/apps/details?id=io.lerk.lrkFM
• Open the app
• Go to settings and choose UI to enable boomark edit mode. As bello
  
• Then, add bookmark and afterwards press delete. Then the app will crash.
• App: lrkFM version 1.6.4
• Operating system: Oppo a57 android version 6.0.1

Recording Of The Bug

Hello developers.

After adding a bookmark, i trying delete it again, and yeah, bookmarks are erased. But the app also crashes after the bookmark has been deleted.

Reproduce of the bug follow the steps below

1. Open the app.
2. Go to settings and choose UI to enable boomark edit mode.
3. Then, add bookmark and afterwards press delete.
4. Then the app will crash.

lrkFM app version 1.6.4
Operating system: Oppo a57 android version 6.0.1

Recording the bug on youtube

My Github Link

https://github.com/shaphir

Proof of work
https://github.com/lfuelling/lrkFM/issues/15