B4J Question upgraded to b4j 10.20 - no layouts will load

Hello all, I hope all is well.
I have an issue where B4J will not load any layout files after installing 10.20.
When I select a layout from the file menu in the designer I get an error.

An error occured.
Error loading file.
Array dimmensions exceeded supported range.

The project compiles and runs fine as well as can build standalone package.
I just cannot load any layouts for editing.

Is there any advice out there?
Thanks.