rsgislib throwing error, but only on certain tasks (exit code -1073741819 (0xC0000005))

I'm doing some OBIA and have a conda environment with rsgislib up and running (installed via -c conda-forge).

I can use functions like imageutils.stackImageBands with no issues. But when I run segutils.runShepherdSegmentation or rastergis.populateRATWithStats there is an issue. When running either of these through PyCharm I get 'test' is not recognized as an internal or external command,operable program or batch file followed by "Process finished with exit code -1073741819 (0xC0000005)".

If I run from the script through anaconda prompt (run as admin) I get the test error then the script stops.

To add to my confusion, the ShepherdSegmentation produces the segmented image file absolutely fine, but crashes the script after it has finished.

Can anyone shed any light?