What version of Incoder?
Can you post a copy of one of the XPression Codec files that fails to ingest?
Can you post the XPression Incoder logs that has ingest failures in it?
I don't think this is the problem, but can you make sure the XPression Codec has also been installed on the computer running the XPression Incoder? (Reboot after installing)
Do you have the setting "re-encode files that are already in the XPression codec" enabled on the Incoder? (Found the in processors tab)
You may want to reach out to Ross Tech Support to get this resolved.
#XPression