String Variable error

Hi…
I am facing the following error on String variable, So, i am unable to use the variable.Screenshot from 2021-03-14 21-08-40

I cannot see any errors in the catalina.out log…

I am using UBUNTU 20.04, Cuba Platform 7.2.11, Cuba Studio 15.2-202

Please help to solve the issue…

Hi,
This looks like internal IntelliJ IDEA problem.
The log it says about can be opened with Help -> Show Log in Explorer menu item.