The filename doesn't contain any of those characters so I don't understand why it's displaying this message? Very annoying.

Hi... What is the filename you are trying to use?

                                                                

Peter
Forum Administrator

www.reallusion.com

I tried a bunch of different filenames including literally just typing out a single letter such as "a" and the message would still appear.

However I think the issue was a result of using an alpha stage "motion capture from video " software by the name of plask.
When I repeated the process instead using deepmotion's "motion capture from video" the problem went away.

I hope that makes sense, I'm currently sleep deprived and relatively new to rigging and reallusions software.

tldr; It seems Plasks exported model interacted weirdly with 3Dxchange