The .ssim file name that I’m using is: BlackHills20230119.ssim. I did specify custom folder names as part of an attempt to avoid the non-Base-64 error but the error was present before then, back when the folders were being auto-populated. When I do run the scenario using only one core, it does work, and outputs are being written into the custom specified modeloutputs20230517 folder. When I try to run things with multiple cores, a BlackHills20230119.ssim.temp folder is being created but is empty. Everything is being done on a local drive.