You are not alone this. I have also been suffering from this has since the start of today and at some point yesterday. I guess there's a glitch with the front end which cause those error messages to appear. Still experiencing it as I speak. Anytime I submit a message and receive that message, I simply move on the next one as most times those comments seem to later on reflect. Sending more than once is what result in many to reply to a particular post or comment and it reflects multiple times.
For the mean time, it's best to endure this till the developers in charge of the frontend rectify this issues
I hope it is rectified on time so you don't disturb us from doing our duty.
I hope so too. So we don't get to be frustrated by it.