Folders with dot cant backup

Hi, I have a problem. Duplicati cant make a backup of the folders with a dot in a folder name, like this

2020-11-14 14:23:26 +01 - [Warning-Duplicati.Library.Main.Operation.Backup.FileEnumerationProcess-FileAccessError]: Error reported while accessing file: C:\Users\User\Desktop\City ex\City\2015\04\08.04.

Is there any way to solve that?

Windows has problems with folders ending with a dot. You can do an Internet search for lots of examples.
Is your folder ending with a dot or a space or is the only dot between the 08 and the 04 in the folder name?
I’d be rather surprised if a dot in the middle broke things. Those are too common. Check name carefully…