# OpenMC running error - Command 'openmc' returned non-zero exit status 255 **URL:** \ **Category:** User Support\ **Created:** [February 27, 2021, 5:56am UTC](https://openmc.discourse.group/t/openmc-running-error-command-openmc-returned-non-zero-exit-status-255/1036 "2021-02-27T05:56:37Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Marco](https://avatars.discourse-cdn.com/v4/letter/m/a698b9/32.png) [@Marco](https://openmc.discourse.group/u/Marco)\ **Post date:** [February 27, 2021, 5:56am UTC](https://openmc.discourse.group/t/openmc-running-error-command-openmc-returned-non-zero-exit-status-255/1036/1 "2021-02-27T05:56:37Z")
I want someome to help me, please? CalledProcessError Traceback (most recent call last) in ----\> 1 openmc.run() ~/.local/lib/python3.8/site-packages/openmc-0.12.1.dev0-py3.8-linux-x86\_64.egg/openmc/executor.py in run(particles, threads, geometry\_debug, restart\_file, tracks, output, cwd, openmc\_exec, mpi\_args, event\_based) 216 args = mpi\_args + args 217 → 218 \_run(args, output, cwd) ~/.local/lib/python3.8/site-packages/openmc-0.12.1.dev0-py3.8-linux-x86\_64.egg/openmc/executor.py in \_run(args, output, cwd) 26 # Raise an exception if return status is non-zero 27 if p.returncode != 0: —\> 28 raise subprocess.CalledProcessError(p.returncode, ’ '.join(args), 29 ‘’.join(lines)) 30 CalledProcessError: Command ‘openmc’ returned non-zero exit status 255. ---
**Author:** ![paulromano](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/paulromano/32/486_2.png) [@paulromano](https://openmc.discourse.group/u/paulromano)\ **Post date:** [March 2, 2021, 12:38pm UTC](https://openmc.discourse.group/t/openmc-running-error-command-openmc-returned-non-zero-exit-status-255/1036/2 "2021-03-02T12:38:47Z")
The `openmc.run()` function is equivalent to calling the `openmc` executable from a command line. I would suggest running the executable from a command line to see the full output, which should give you more information on what error is occurring.