Jyri T.
I rolled back to version "G" and Sonar is no longer crashing when I try to open a big project. It started with version "H" and didn't go away with "I" so I decided to take a step (actually 2 steps) back.
 
Now it works fine.

It's probably extremely unlikely your issue is similar to OP unless you use exactly the same plugins, windows versions and hardware. But at least for now your issue is resolved.

Whether later versions of Sonar will resolve your issues, without having to debug your projects (trying to locate the root cause) remains to be seen.