Locked - Elements 10 + [Suddenly unable to use photo stack to process my macro photography shots.]

I need someones help!

I have learnt how to photo stack to process my macro photography shots.

Elements 10+ has suddenly decided to 'not respond' when I get to the photo stack command.

I have not made any changes, have not contracted a virus, have not altered the process in preparing all (10) layers.

My desktop is running windows 10.

Does anyone have suggestions that may help?