I use Adobe Media Encoder V12.1.1(Build 12) on a Mac.
I've noticed recently that the pulldown pick list of file formats (as in h.264, .mov, etc.) and the list of presets (Vimeo, Apple Pro Res, etc.) are unavailable. The settings are stuck on one preset and I cannot change it. It is stuck on h.264 and a Vimeo Codec. It is stuck in both the Output Settings screen and in the queue screen. I've tried changing it in the Queue and when I click on the highlighted format or the highlighted codec in the queue list, I get a message: "File Import Error - Could not read from source. Please check the settings and try again."
I am able to import a codec, but only those that match the H.264 format that it is stuck on.
I'm kind of dead in the water with respect to using AME until I can resolve this. Help!