Compile Error

I’m trying to recompile the Combine Apc wih some fixed animations, but I get the following error:

  - missing animation blends. Expected 2, found 3 

The specific section of the .qc looks like this:

$sequence weapon_pitch "aim_up" fps 30.00 {
  blendwidth 2
  blend vehicle_weapon_pitch -45.000000 45.000000
 aim_up aim_down

I don’t know much about animations, but I think it is looking at the “aim_up aim_down” part. The error told me it was in the line below that part, but when I added “aim_left aim_right” right below the “aim_up aim_down” I got the same error, but with a 4 and 5 instead of a 2 and 3.
Could someone please tell me what the issue is/how to fix it?