My server recently went down and my clients solutions were stuck searching for external/internal infinitum. Could not abort. On mirrorsync side is there a way to set the script to exit if it can't find internal nor external?

This was a bug that could happen when trying to initiate a sync with no working network connection. It is fixed in the latest version on http://mirrorsync.com(version 2.403). You'll need to re-copy and paste the script steps to apply the fix.