@drdave79 if /etc/emulationstation doesn't exist it would break standard retropie - that's where the carbon theme is kept. can you show a screenshot of how you're trying to navigate to it or something like that?
Do you know how to remove the "custom override" so the es_systems.cfg gets properly updated?
it shows you where it is in the error message - just delete the whole file. obviously that will remove all the custom changes you've made, so if you want to just fix this system you replace it with what's in /etc/emulationstation/es_systems.cfg for the psp.