<Obligatory thankyou thankyou thankyou>
Eensy-weensy issue. My butcher shop is chock full of 'unknown frozen creature substance'. Of course, once I noticed, it had already piled up, so I don't know which creatures all produce it, but I CAN get rhinoceroses, giant mountain goats and GCSs to produce 'rhinoceros unknown frozen creature substance', 'giant mountain goat unknown frozen creature substance' and 'giant cave spider unknown frozen creature substance' respectively. These do not account for the plain 'unknown frozen creature substance'.
Version 42.06 Phoebus, with Accelerated module
DF version 42.06 Windows, with LNP 42.06-r02 (kept Phoebus, pasted MM over), DFHack enabled
Fort mode
Troubleshooting so far: removed power cord, waited 15 seconds, plugged back in. Re-pasted MM and Accelerated into the save folder. Attempted butchering all species in fort, so far: GCSs, rhinos, giant mountain goats.
Save is at
http://dffd.bay12games.com/file.php?id=11964.
I did try searching, but all I could find were references to a bug in 40.<06 with compiler flags, so don't think it's related. Also took a peek in creature_large_tropical, but I have no idea what it's supposed to look like to begin with. Please tell me if I've gone and done goofed something up!
Edit: I just watched a child eat some of the rhino stuff, so at a minimum it resembles food, though it doesn't appear to rot. Added GCS and giant mountain goat.