Vegas OFX: Mocha Pro Bad argument provided

Trying to use Mocha (for the first time in a while) to do some masking in Vegas 13 (sony). I’m running Windows 7, 64bit.

When I turn on the Mocha UI I get a bad argument provided error.

The file is a simple, 2D 720p mp4 file (from Handbrake).

Can you be more specific? Is the bad argument there as soon as you open Mocha or do you do a series of steps to get that? adding details can help us track this issue down for you.


Yes, the bad argument message is there as soon as the Mocha interface opens.

I installed the latest update, but it had no affect on this error.

OK, we think this is a bug. We will see if we can reproduce it. Can you try using an image sequence and seeing if you get the same bad argument?

Thank you for letting us know about it,

It may be a few days to get access to my editing computer.

So…literally, create a Vegas project using some still images (jpeg’s) instead of a MP4 file?

Yes, I want to see if it’s related to the codec.

As it happens, the project I am editing contains a video clip and still image. I am trying to create a mask that composites them to hide some people moving in the video clip.

I deleted the video clip and applied mocha to the still image alone and the mocha GUI opens correctly.

Here is the media info report for the video clip.

8449.txt (4.2 KB)

Interesting, can you try an uncompressed .mov file and see if it opens for you? That might be a good workaround for now.


I would prefer not to. Vegas 13 does not work well with them.

Does it work well with image sequences? If so, try that as a workaround until we find the fix for this.

Has this been solved in the new (2020) release?