iTunes won't let me add a certain "MP4" video file.

[jamesryanbell]

Only one file does this, and it's 4.35GB. None of the other files are over 4GB. Is that an issue?

 

[Mal]

More likely it's just in an incompatible format. Not all MP4's are necessarily the same.

Might consider dropping it in Handbrake and converting it to iTunes format.

jW

 

[spinnerlys]

You can also use VideoSpec to analyse the file and post the report here.
Also use VideoSpec on a working .mp4 file and post that report too (as I don't use iTunes for videos).