A Server Error Message when trying to attach a file

[HotAirWH1]

Is anyone other than me having an issue attaching files to Messages?
I'm getting - A server error occurred. Please try again later.
The files are small, around 100KB so that shouldn't be the problem.

 

[N2BUICK]

Yes I tried yesterday evening, got the same message.

 

[SGRIM]

@JayC