Any idea why this happens every time after several minutes of opened app? Is the huge number of rigs a problem (350)? I have to kill process with Task Manager every time. Other groups with less rigs don't have this problem..

I had this same memory error happen with my 4 rigs. Error happens about once a week. Have not seen the error yet after upgrading to 5.0
I had the same issue on one of my PCs. It was not more than 30 rigs. I found no dependencies why.