Robert has already tried deleting thousands of ancient posts to no effect. IMO, it is now obvious that the problem does not solely lie with the accumulation of posted images, but with the server. As SB indicates, server logs should be available for scrutiny by our Server Admin at the time the problem suddenly appeared. The fact that this problem has been present since the beginning of November without any signs of a fix makes me wonder if the Server Admin is actually actively pursuing the problem.
Spit at t'other place.
Version 57.0, first offered to Release channel users on November 14, 2017