[Mol Smith]

After no end of similar problems trying to render a complete 2 hour film after a year of editing, here are a few things to try.
First – back-up somewhere safe, your exiting projrct files and any renders.

1) delete all workarea renders completely.
2) Clean the Media cache database.
3) Safe the project and close premiere.

Reopen premiere
Open the project and render entire work area.
Save the project. Close Premiere. Reboot pc.

Start premiere, open project, export media.

If it then fails…

Close preimiere.
Open Adobe Media Encoder. Try brining in the project and render out from there.

mol