Hi Andrew,
Neither of these help the problem - the film / scene colour settings in the post process volume simply don’t work until we try the ‘fix’ in the other thread. Other settings (e.g. Depth of Field) work perfectly normally.
After the ‘fix’, lighting is completely washed out but post processing does work.
After saving and quitting, then reopening the editor and map, everything is back the way it was before we started (post process is broken as described, but lighting is back to normal).