MOSAIC doesn't work anymore in all IMs

[BDiana]

Unfortunately, "mosaic" does NOT work anymore.
Inputted images receive NO effect when 'mosaic' is choosen.
Why having a non-functional function in the studio?

[BDiana]

I should probably add, that we used clipboard and append to
create an image list and to get the mosaic function to work.
No GO!
Then we tried via composite. NO GO!
I am off to GIMP!