Use of function save is not supported on a thread-based worker

I just upgraded to Matlab 2023_a from Matlab 2019_a and suddenly I'm receiving this error:

"Use of function save is not supported on a thread-based worker."

I call save from within the parfor loop. It has never been a problem before the Matlab upgrade.

Answer 1

[Walter Roberson]

parpool("threads") and backgroundPool did not exist in R2019a, so you could not have been using them back then.

If your code has not changed, then possibly your parallel preferences have been set to start thread-based pools.

https://www.mathworks.com/help/parallel-computing/parallel-preferences.html

[Meredith]

Yes, it was using the "threads" cluster instead of my local cluster ("Processes"). When I switched to Processes everything worked as usual. Thanks!