'XXX' is an invalid name on this platform

In the “Media Files” window pane, when I try to rename a “folder”, the above message is what I get. This kind of message is very unhelpful. It needs to be instructive.
AJ

Hi, @alan
What are you trying to rename it to?

@alan,

Are you trying to do something like this&

I can no longer replicate the error I was getting (using “rename” to change the name of a folder in the Media Files window - nothing to do do with an invalid character btw)

AJ