keen-UnUnMult: A workaround for the UnMult bug in Ae 13.1 (CC 2014.1)

The CC 2014.1 release of After Effects (version 13.1) has a nasty bug which causes the application to fail on effects with no properties, like the popular Red Giant Software’s UnMult effect [link], with a never-ending barrage of error message windows:

After Effects error: internal verification failure, sorry ! {unexpected match name searched for in group} ( 29 :: 0 )

The Ae team is working on a fix [link], and it should be out soon, but in the meantime, I’ve developed a workaround.

I’ve written a script, keen-UnUnMult, which searches a project file for any instance of UnMult and replaces it with one of three unmultiplication alternatives:

Each UnMult alternative has pros and cons. Channel Combiner plus Remove Color Matte is a good match for the look of UnMult, but is limited to 8bpc. Set Matte plus Remove Color Matte works at 8-, 16- or 32bpc, but is not mathematically or visually identical to UnMult results. Video Copilot’s free Vibrance effect [link] can do unmultiplication, but it’s third-party and produces slightly different results.

None of these replacements may be perfect, but if you are having trouble opening and using an older project with the current 13.1 release of After Effects, this script may be able to help you.

You can download the script below. Unzip and drag the keen-UnUnMult-v1x3.jsxbin file into your ScriptUI folder:
PC: C:\Program Files\Adobe\After Effects CC 2014\Support Files\Scripts\ScriptUI Panels
Mac: /Applications/Adobe After Effects 2014/Scripts/ScriptUI Panels

If your UnMult project crashes immediately upon opening in Ae 13.1, hold the Shift key while opening the project. This opens the project but does not open any comp viewers and should get you past the error loop. From the Window menu, select keen-UnUnMult, choose your replacement method, and click the button.

This is working nicely here, but I haven’t done exhaustive testing. Please report back any issues and I’ll try to get them fixed ASAP.

I’m taking a page from Jeff Almasol’s book here: if this gets you out of a jam, please consider making a donation to a charity that matters to you and tell us about it on Twitter with the #devforacause hashtag.

Download keen-UnUnMult-v1x3 [link].