It was all saved on an external disk (I know this isn't recommended) so it could be shared across 2 different computers (both Macs running Monterey).
When I opened it on my computer I couldn't select a source patch for the audio. I deleted several audio tracks and interpreted the chosen footage in the source monitor to contain 1 audio file instead of 8.
I created a new sequence, copied and pasted the clips to that and it worked for a while, but then when I tried to add new clips they showed no audio levels and wouldn't play at all. When I open them in the source window they only show the audio file window with a completely flat line, even though there is definitely audio on there.
When I try and play anything on the timeline now it won't play there or in the source monitor. I undid everything I'd tried, created new timelines, matched settings to the clips, but still no playback and intermittent unavailability of audio source patch.
I opened it on the original computer and the same problems persisted, so I opened the last saved project file before I'd moved it to my computer. There is still no playback, the source patch has disappeared again, even on the new sequences, and nothing will play.
It just seems to be glitch after glitch rather than one specific problem.
We're both running Premiere 22.2 on an Apple Mac Monterey 12.2.1 and have created Apple ProRes422 proxies.
storing media on an external drive IS recommended... What are your source properties and what kind of camera did they come from? and how did you "delete several audio tracks?" do you mean you deleted tracks from your sequence? Are your proxies properly "attached" to your full rez files? 2 ways to check this; turn the proxy option on under your program or source monitor and select the clip and control click and choose "reveal in finder." if the proxies are revealed, the proxies are properly attached. You can also set up the metadata display in the project bin to display the proxy state... I just remember trying to work with material shot on a sony camera (can't remember the model) with 8 tracks that was impossible to create proxies successfully. Had to do with the formatting of the audio on the camera original.. Never simple to diagnose these sort of problems from a distance...