Curve fitting toolbox crushing

After uploading to the latest MATLAB release 2021b and using the latest software on my mac . The curve fitting toolbox is crushing and it is unusable, what could be the source of the issue?

[Matt J]

You should probably talk to tech support.

[John D'Errico]

When you have an error, WHAT IS THE ERROR MESSAGE? Show the complete error message text, so everything in red.

If I must make a wild unsubstatiated guess, you tell us that updated MATLAB. Did you maintain the licesnse on the curve fitting toolbox? Or are you hoping to use the old copy of that toolbox? You cannot do that. But I'm only making a guess.