GitLab

If you try to delete a file inside ckeditor via kcfinder you get an "Unknown error." if the file name contains brackets. Those brackets are generated during upload if a file with the same name already exists (e.g foo(1).jpg).

Steps to reproduce:

1. Open a form which contains a text field with ckeditor (e.g. create an event)
2. Click on the link button of the ckeditor toolbar
3. Click on "Browse Server" to open kcfinder
4. Download a file via its context menu
5. Upload this downloaded file again
6. Note that the file is uploaded with brackets in its name
7. Try do delete this file via its context menu
8. Note message "Unknown error." and that the file has not been deleted

So in short you can not delete files which were renamed during upload because of already existing file names.