hi see attached screenshot. i cant remove this folder, what is it and how to remove ? I use windows 10. i cant see that folder in windows explorer - only opus
It looks like you are using Microsoft "One Drive". If so, then it should be harmless. Although i can't figure, why you can't see it in the Explorer. Maby you have set it to hide certain (system) folders?
Thanks, how can I remove this strange folder which is only visible in opus? I can't delete via opus
Which version of Opus are you using?
Try unchecking SkyDrive in the Desktop section of Preferences / Folders / Virtual Folders.
The folder name should appear as "OneDrive" instead of ::{018D5C66-4533-4307-9B53-224DE2ED1FE6}, so something odd is going on somewhere, but hopefully that will hide it.
If that doesn't work, you can go open Folder Options and on the Filters tab put the folder name into the Hide Folder / Folders field, then save the format for the Desktop folder.
thanks very much that solved it 
Try unchecking SkyDrive in the Desktop section of Preferences / Folders / Virtual Folders.
Regards Nolan
Using Opus version 11