It's obviously not something normal. Being generalized, it's most likely server side. My "solution" is a temporary work around. Glad it's of help.

Just happened to me again. Posting this on Peakd. Kind of a pain, but it's introducing me to PeakD, and it's not bad.

Edit: now I see that each "attempt" that I got an error on actually posted.

Deleted them. Pain in the ass. Had to log in to HiveSigner each time. Maybe that's because I'm on my phone ...

... might be time to go on holiday.