It failed with the attached error
As you can see the directory is chmod 755 so there is no reason it failed, the red error is also suggesting it is a language setting.
I also tried to rename a file and that failed with the same error

Error! Item could not be renamed
Code: Select all
Content -> File Manager -> Settings
[x] Enable advanced mode?:
Lets you gain access to whole cmsms filesystem, not just /uploads/ (if allowed)