After I updated to 1.3.40, everytime I try to open a GUI-designer there is an “ArgumentNullException” for the parameter “key”.
The Designer is then shown but sometimes throws NullReferenceExceptions.
It still somewhat works but you might want to have a look at that.
thanks for reporting this. I tried to reproduce here but failed so far.
Does this happen with all forms you are opening in the designer ?
Can you please try with one of our examples or send me a small repro case ?
You can reach me at frankATiceteagroup.com