costume editor goes blank when switching costumes...inconsistently

[ksdavidc]

Describe the bug. What is going wrong?

The overt sign is that the costume editor will “go blank” at unpredictable times when switching costumes. If I switch to another tab (like code or sound) and return, it is okay.

Attached is a console log. It appears to be related to the opacity slider.
scratch.mit.edu-1697915677926.log

What is causing the bug?

not sure.

Anything else?

No response

[ksdavidc]

I discovered that to my surprise ScratchAddons also had an opacity slider. I thought it might be a conflict between the two. Alas, even if I have ScratchAddons completely disabled, I still get the error.