I run the 'PuLP' solver on my OSx and after some conda updates it stopped recognizing the solver. I call: solver = pulp.get_solver('PULP_CBC_CMD') prob.solve(solver) I get: pulp.apis.core.PulpSolverError: PULP_CBC_CMD: Not Available (check permissions on /opt/anaconda3/envs/my_env/lib/python3.8/site-packages/pulp/apis/../solverdir/cbc/osx/64/cbc) When I asked for a path I got: pl.pulp_cbc_path Out[9]: '/opt/anaconda3/envs/ExMAS/lib/python3.8/site-packages/pulp/apis/../solverdir/cbc/osx/64/cbc Maybe interestingly, my conda env is for python 3.9 and my PuLP is in3.8 folder My PuLP is 2.6.0 Thanks Continue reading...