Hello Guys, using MAC Book Pro with OS High Sierra 10.13.6 together with Parallel 13 and Window 7. Worked well with 3D Programm Rhino 5. Few days ago, system crashed and telling there is a problem with graphic card and memory. My MAC is very powerful and after restart every window program such as Rhino or Microsoft went pretty slow or telling there is not enough memory. I thought updating to Parallel 15 could solve the issue if some files are corrupted. Installation of Parallel 15 went fine but I am stuck to restart Parallel. Black screen is asking to press CTRL, Alt and delete to restart Parallel. Have done it with the keypad and the virtuell keypad but showing no sign of restarting. I have read that Parallel could be started in save mode but I cannot find this option at all. Help would be highly appreciated. Thanks Markus