@jordan.howell2, no, sorry. Thank theano is no longer being actively maintained and they haven’t had time look into the issue.
I’m very confused about your particular problem. You are able to compile and run 64 bit models with cores=1, but when you make a process pool, they can no longer compile the models. To me, this indicated that the spawned processes were not using the same compile options or compile than the main process. I thought this was due to a change in the environment variables or conda environment but my tests on windows did not show any undesired change of the kind. Maybe it’s because I’m just not able to reproduce the error you observe. But in the end it’s very hard to blind debug. I’ll try keep searching a but next week