I dont know what avid's error (64) means, but you may reference the install guide that says: "Avid NEXIS Version Downgrades Installing an older software version on Avid NEXIS systems is not supported and can result in unforeseen consequences, up to and including data loss." I have a few theories for you, but they all involve (in bold)

what is your media creation/render codec set to?

the best source right now is going to be this KB article: https://kb.avid.com/pkb/articles/troubleshooting/en239659 the answer is probably "crowdstrike"

[quote user="Ajay Yumul"] Bug Number: MCCET-4952. (macOS) In some instances, audio drop outs, distortion and sync errors occurred without effecting video playback on Apple Silicon systems. [/quote] this bugfix does not appear in the 2023.12.2 readme that is linked in your post. Is that a documentation ommission, or did the fix not make it

check this thread, worth a shot. https://superuser.com/questions/1555186/disable-virtualization-on-a-surface-book-3

what version of nexis, what version(s) of nexis client? what does your nexis network infrastructure look like? Nexis and Clients on same subnet? routed nexis with remote hosts config? I have multiple mediacentral environments with far more workspaces than drive letters using UNC mounts successfully for years and years. I also just tested my lab win10

what storage are you writing TO?

[quote user="matsta"] Thank you for the response. It's a bit disheartening that in the case of losing the installer for an older version of Media Composer, for which I have a valid license, the user is left to fend for themselves. Now, because all the older MC installers have been removed, the only option left for me is to purchase a subscription

23.12 is my current test build, as I really need the new batch import/reimport function to finally move the last holdovers from MC2018.12.

awesome! Will try to get started on testing today with mc2023.12 on macos13.6.4 with ultrastudio extreme on mac studios.