New browser error when trying to post a reply to a forum post

Dear Sirs or Madams,

Over the past few weeks, I am getting an error any time I try to respond to a Forum post if I am not logged in. If I am not logged in and hit the "Reply" button, it prompts me for my credentials and then, after 20 to 30 seconds, I get the following error:

I cannot recover from the error using browser commands and must resort to find the URL to the post I wanted to reply to. Of course, when I do get back to the post, the reply I have written is gone and I must reconstruct my reply by memory. I've experienced this error on multiple browsers (OS X Safari, Firefox, and iOS) as well as a multiple Macs and PCs. I never experienced this behavior until the last few weeks. Has anyone else reported this experience, and if so, is there a worakround or expected resolution date?

Thank you,

Shawn