I am a long-time user of Psychtoolbox. I have a trial version of Matlab 2020a + image processing toolbox. I am using a Mac OS Majove version 10.14.6. Matlab 2020a trial version was working well until I attempted to install Psychtoolbox to display my processed images. Stupidly, I failed to keep track of the battery life on my computer, and the computer appeared to lose charge during the Psychtoolbox installation. However, when I replugged in my computer-- the successful download message appeared (thus, I thought a crises had been averted). However, Matlab 2020a trial version no longer functions. I only see the “spinning wheel of death” every time I open it. I have trashed/reinstalled Matlab 2020a trial version 3x now. I have also trashed the Psychtoolbox folder. Finally, although Matlab 2020a trial version does not function for me to type into the command window…I have an old version of Matlab 2015 on the same laptop that does work-- and I used the PsychtoolboxRoot command-- in case somehow there was a hidden folder that I could not see. However, it simply says it cannot recognize the command. Does anyone have other suggestions I can try? Thanks so much.
All Psychtoolbox does is add a folder to the java class path, and its folders to the Matlab path. So if due to some unlucky power-outage something would go badly wrong during writing of those files, maybe that could prevent Matlab from starting? Other than that there ain’t anything in PTB that could cause this.
If you search for the javaclasspath.txt file, then PTB will have created a backup of the original file under javaclasspath.txt.bak, so you could rename that .bak file to restore to the original.
The path file you’d need to repair yourself. I assume there’s some instructions somewhere on Mathworks site.
More likely though the startup problem has nothing to do with PTB.
-mario
Thank you so much Mario for the very helpful suggestion. Although returning to the original javaclasspath.txt file did not fix the issue, it provided valuable information that the Psychtoolbox files were not accidentally corrupted during the install/power outage. I ended up resetting my Matlab preferences manually – and this solved it. Thanks again for your quick response. It really helped me.
https://www.mathworks.com/matlabcentral/answers/99625-how-do-i-regenerate-my-matlab-preferences