I have the exact same problem. I played with all the settings and no combo is working, it used to work good in past builds. Hope getting a fix in coming builds.
Just to help diagnose what is broken, can you describe in more detail what errors you are getting? There are actually two different errors explicitly referred to in this thread. The original poster was getting something like "make sure the file is in the right location" (which I've never seen), but
Sauzee is getting "Direct show unspecified error- Code 0x80004005" (which I HAVE seen many times).
A post like Sauzee did in the other linked thread with additional detail would be very helpful if you have the means.
It would also be nice to know some system details:
1. Windows Version
2. Any Installed Filters (this shouldn't matter in RO mode, but that isn't
quite true yet, especially for DVD playback and subtitles)
3. GPU type and driver version
4. CPU details
5. Are files local or network?
6. Are you using Bitstreaming or PCM output?
7. Are you on a Library Server Client or not?