404 Page not found Error

All,

I am having an issue with Open edX Tutor… We have it set up on a LAN and we had courses we imported and randomly certain courses will break and give a 404 Page not found error. For instance a course that worked fine yesterday… no longer works today and it happens at a crazy rate, we can reimport the course and its fixed, it seems random. I have checked the URL for LMS_BASE and PREVIEW_LMS_BASE and they are different. Not sure what is causing it but it seems very random and certain courses just break. Not sure what else to check, can’t seem to see any rhyme or reason in the logs…