I have a candle flame image with which I'm using an .mp4 for the candle flame video, and another b/w .mp4 for the alpha. It works usually (and always on our other computers), but every now and then one of the computers gives me a fail to load error, with the "missing codec" error as the reason. It's a Windows 10 machine, so, yes, the .mp4 codec is on there. Also, it works from time to time, on various projects, using the same video--but then it will just stop working, and all projects (which work fine on other computers) which use an .mp4 give that error. The last time this happened reinstalling iClone fixed it, but that didn't help this time.

How can I fix this? Using other codecs shouldn't be the solution, as (a) this works fine on our other computers, and sometimes on the problem child, and (b) that would involve relinking the files across many projects, to a much more memory-intensive format.