eM Client crashes with google account

I installed one smtp mail account and one google account for contacts and calendar.
I can open a calendar item exact 3 times before em Clint crashes.
I tried it on a fresh Windows 10 install - same! It crashes.
I am frustrated with this product - do I have to go back to outlook?
My support case is now open since 24 hours - sorry, I have to work.
I hope someone here has a solution.