How to get rid of notes "null" in folder "Konflikte"

A few weeks ago I made a very large note with the desktop application (Win 10, 64bit with Joplin 1.0.137), but it failed. Unfortunately I synced this note to my Tablet (Android 7.1.1 with Joplin 1.0.239). On the tablet there is now a folder “Konflikte” (conflicts) with two notes “null”. How do I get rid of them? They cannot be deleted manually.

Could you send a screenshot (so that I can try to replicate this)? What happens if you click on the “null” notes?

Sure, here it is (Medion P10506):

When I click on one of the notes, I see nothing. (On top the folder “Konflikte” is farther shown).