Anyone know why this is happening?

[JustAQuickiePlease]

When I try to post a message, a pop up appears (see image.)

Oh yes, I am getting that too, only on laptop though, not on iPad.

The message does not seem to post/takes a long time to post, but when I leave the thread then return later, my message has posted correctly.

There's another thread about this - See Site Problem posting on a thread.