How to investegate MySQL crash on windows?
I figured out a solution.

I run MySQL via the command line 

I disabled this line log-error=.... from the my.ini file.

I stopped MySQL service.
Then I opened a command line and run this

mysqld.exe --defaults-file="C:\ProgramData\MySQL\MySQL Server 5.6\my.ini" --console


This showed me that I run into a bug with MySQL