Typically that error shows up when a particular limit has been exceeded, such as too many vertices for a mesh. Unfortunately, no one has documented what the limits exactly are or how to determine which particular limit causes the error in a compile.

Sometimes a missing bone problem like this can be fixed by using a set of $definebone lines in the QC file. You can make the lines 3 different ways:

1. Choose the "Include $definebone lines (typical for view models)" option when decompiling the model in Crowbar.
   
2. Compile twice in Crowbar - First time, use the 3 definebone Compile options to get the lines in the QC. Second time, compile as you would normally (without using the 3 definebone Compile options).
   
3. Write them manually.

Maybe the mesh SMD files are using bone names different than the QC. You can view the files in a text editing tool.

My guess is that the animations are stored a special way, like the L4D2 survivors. For those, I have yet to figure out the format.

Would you list some of the MDL files Crowbar failed to decompile?

Yes, having a few MDL files would help. Maybe I can determine if other files are even needed in the new format.

Portable binary:

• Crowbar_2016-11-03_0.36.7z (Released 03-Nov-2016) (301,068 bytes) (MD5: d762d59d5dd61da4f8ae23702850297b ) (Hash tool used: HashCheck Shell Extension[code.kliu.org] )

Source code:

• Crowbar_2016-11-03_0.36_source.7z (Released 03-Nov-2016) (409,345 bytes)

Changelog:

=== Unpack ===

• New Unpack tab. Unpack and extract files from one or more VPK files.

=== Decompile ===

• Decompile MDL version 36 (only reference mesh, physics mesh, and animation SMD files; QC file is incomplete).
  
• Decompile MDL version 37 (only reference mesh, physics mesh, and animation SMD files; QC file is incomplete).
  
• Decompile MDL version 47 as if it were version 46.
  
• FIX: Using "$DeclareSequence QCI files" decompile option fails to complete for models without texture file names, which is common for animation-only MDL files.
  
• FIX: Decompiling fails to complete for models without texture file names, which is common for animation-only MDL files.
  
• FIX: Decompiling of a model that has bone names with spaces causes Crowbar to write incorrect $CollisionJoints block of lines and to write $CollisionText lines that should not be there in QC file.

=== Compile ===

• FIX: After selecting a QC file via Browse button, the command-line text box is not updated with the new QC file name.
  
• FIX: Missing compiled files when Compile to Output Folder Full Path is set to the default that the model compiler uses.

=== Preview and View ===

• FIX: Pasting in a file name that is surrounded by double-quotes prevents using anything else in the window.
  
• FIX: When opening Crowbar that has a model in View and a model in Preview with different model versions, one of them would show the incorrect model version.

I have not heard of anyone else having trouble decompiling on Mac. I am unable to test on Mac.

You could upload the "spy.mdl" file that you tried to decompile and I can check that it is in the correct format.

If it is not in the correct format, then you would need to find a different way to get the correct file.

If the file is in the correct format, then maybe there is a problem with the byte-ordering (big endian on Mac versus little-endian on PC). To fix this in Crowbar would probably involve quite a bit of work. Perhaps PlayOnMac has an option to handle different byte-ordering.

That error means the MDL file is corrupt or not in the format that Crowbar can read.

Example model files would be useful.

No.