KeepSafe is not allowing me to make revisions of any file with the .css file format. Does not work manually (right-clicking file and choosing "Create new revision") or automatically (adding file extension in KeepSafe and saving file). In both cases, KeepSafe creates the file in the storage area, but the file size is 0Kb (opening the file proves that it is indeed empty).
Also, there is no KeepSafe tab when looking in a file's Properties tabs (as stated on page 27 of the User Manual).