Error: The following extra files have been found:assets

I cant update to version because this error, I already put it in maintenance mode but this error still persists.Thnks you’ll.

“Extra files” here means: files and folders that don’t belong there.
So to successfully perform the upgrade, move the mentioned files and folders out of your nextcloud directory, continue/ retry the upgrade and after the update was complete and successful, you can move the files/ folders back in.

Regarding the folder asstest: I think it is not part of Nextcloud any longer. I don’t know if this folder contains any data on your server. If this folder is empty, I think it is save to keep it out of the nextcloud folder (and remove it after some time if everything works fine).

thank you Schmu, i don’t used the automatic update, i maked the update manually and it worked with some errors but it worked.