I have suddenly lost the ability to convert to DiVX with Virtual dub

[DaneClark]

I used to work just fine, but now for some reason it keeps saying "video compression error. The source file is not acceptable (error code -2)" it is happening on files that it had no problem converting before.

[gll99]

Check the framesize of your input file or filter output if you are resizing before compression.

[jagabo]

That is almost always because you tried to compress an odd frame size like 641x480.

[DaneClark]

It's 640 by 480.

[redwudz]

Make sure the frame size is an even number, IE, 640 X 480 or similar. Divisable by two or four might help if you have an odd number. If no help there, try disabling the audio and see if that works. Maybe the audio is the problem.

[mgh]

also happens if frame size is not compatible with profile you have chosen (e.g. HD will throw that error if you use Home Theatre profile)
try unconstrained profile to see if error goes away.

[jagabo]

also happens if frame size is not compatible with profile you have chosen

Ah, good point. Forgot about that one.