Nextcloud App crashing for almost every action

Hi together,

i am using some folders of my server via the external storage app in nextcloud. On one of that folders there
are my pictures that are uploaded automatically via the android smartphone app.
Yesterday i decided to move that folder and all pictures that are included there. After that has been done,
i erased the old folder from the configuration of my external storages app. I went into the nextcloud app on my android smartphone and wanted to change the directory of the automatic uploads to the new one. But since ive done that, i am not any more able to do anything in the nextcloud app. It is crashing randomly for whatever reason when i am clicking on the (via external folders included) folder in my app.
I did reinstall the app on my smartphone several times and also i tried to restart apache and my whole server, unfortunately all of this didnt have any effect on the functionality of my nextcloud app.

Thanks for your help, kind regards