You don't give any details about your format or sequence settings, so I'll be general here.
Just a couple of observations...
The only time limitation messages I've seen (in the last decade) have been resource-oriented, not NLE constraints so if your system doesn't like a 72-minute sequence I'd be looking at drive space or something like that. Have you tried outputting two 36-minute pieces?
I don't understand your logic in using the sequence codec option (which is limited to two specific formats) to control output of the sequence rather than the output "same as sequence" dropdown) options. Personally, I don't use either, I output the sequence as is and transcode in Compressor.
Simple as it sounds, "Codec not found" generally means exactly that, so I'd be looking at whether the codecs need to be re-installed.
Hope this helps