"Max couldn't convert the max file to an FBX file!" error

i have a project with a single max file that holds all the geometry and the animations. everything was working wonderfully until yesterday when i did something in max. since then i get a “Max couldn’t convert the max file to an FBX file!” error every time unity tries to import it. no matter what i try to do - this is what i get. the thing i changed in the max file was really small and nothing that should have made the file so unusable - i flipped some faces, moved a few vertexes around and created a box. oh yeah, i also animated the box. normally, with keyframes for position, rotation and scale. nothing too exotic.
exporting the file to FBX will be the last resort since i don’t know of a way to replace the prefabed max file with the exported FBX and there is a lot of things happening that reference objects from the max file specifically and would be a pain to replace.

i have tried:

  • deleting the object i last worked on
  • breaking up the max file into separate file holding only a few objects each
  • importing the file into a fresh max file
  • doing the import into unity on a different machine
  • spinning around seven times counterclockwise holding a chicken over my head (not really)

nothing seems to help. i am getting the same cryptic message every time, only sometimes it is accompanied with the helpful suggestion to export the MAX file manually to an FBX file. thanks, yeah, i got that.
any ideas as to what could be causing this? i’m on a tight deadline and any help would be most appreciated. also i would like to know what to be careful of when working on the MAX file so this thing would not happen again.



Maybe your file associations got messed up. If you double click your max file in Unity does it open it properly in 3dsMax?