I have the same issue, getting worse and worse. PRT gets slower and slower, then unsresponsive, the completely frozen.
And finally I have to kill PRT (on Mac OS X High Sierra).
It used to happen once in a while, now several times a day… Can hardly finish a backtest.
I noticed 2 things :
1/ The problem happens the same way even I use another Mac.
2/ I I launch PRT on my 2nd IG account (not demo, a real account), it works fine.
So how to reset the environment for 1 particular account, on the server part I support?