"Thumbs > Regenerate" does not work

Hi,
Videos > Videos Manager > (click on the title of the video) > Thumbs > Regenerate does not work.
When you click on “Regenerate” the previews do not change, they remain unchanged

regenerate

Kindly let me know what version of ClipBucket are you using?

Forgive my delay. Latest version CB v. 4.1