I am an experienced MediaLab user and can not seem to resolve this issue. I created an .exp file with 33 questionnaires in it. The experiment runs perfectly fine until ML tries to progress to the 23rd questionnaire where it freezes the entire computer every time. The short cuts to escape ML won't work and I am forced to start Task Manager to escape. I have done a bit of research on the issue and at this point we have already surpassed the 150 variable limit that many Windows 7 users were having issues with in the 2008 version. I have tried everything: creating an entirely new experiment file, reprogramming both the 22nd and 23rd questionnaire from scratch, and running on different computers. Strangely enough when I copy and paste the 22nd and 23rd questionnaire into another .exp file, it runs just fine. Any help would be greatly appreciated.