Happily, the last few posts I have made (all in 2021) do not experience ANY hint of the terrible problems I encountered in 2019. But again, thank you so much Anoree for trying to help me when I was in distress back then.

Sorry, I can't reproduce the problem. (See Site Support thread.)
My best guess is that it's some anti malware program that's interfering with the post and resetting the connection while you're editing.

Another workaround could be preparing the post in another program (text editor, word, whatever) and copy-pasting it into the Forum message.

I see you're using Firefox. Do you use private mode or have you changed the standard settings?

I also now find that I cannot edit my previous Visitor Message without timing out! When I have time, I will try turning a long block of text into a single image file, which I can post with a short text header. Perhaps that let me work around this annoying timeout problem!

I just now tried again to post just the first paragraph of your Lorem Ipsum text in the same forum as you did, and I *still* get this message:
The connection was reset
The connection to the server was reset while the page was loading.

I have not changed my ISP or the browser type I use (albeit I keep up with the latest security-patched version) since the days, now long gone, when I had no problem making long forum posts.

That sounds more like an Internet connection or browser problem.
The BBS has no time limit set on posting new messages.
Other possible reasons could be anti malware (like a virus scanner, scanning all Internet pages for malware) or a router with embedded proxy service.

Whenever I try to post just the first paragraph of your Lorem Ipsum text in the same forum as you did, I get this message:
The connection was reset
The connection to the server was reset while the page was loading.

I guess the Content Management System justs HATES me! <sniffle>

In days gone by, I did encounter the 10,000 character limit and so split a longer post into multiple parts.

A limit to 10.000 characters for a post is in place since the Forum exists.
I successfully posted a message reaching the limits in the Site Support threat.
(See Lorem Ipsum post)

The BBS apparently apparently uses at least 30 characters for formatting information, though. When copying exactly 9.990 characters, I got a warning that the post contained 10.020 characters and had to be shortened. After deleting the last 20 characters of the post, it was accepted.

Thanks for the quick feedback, Anoree. I tried again today and discovered something. Very short posts of a few words encounter no problem. But the longer the post (even a mere two short paragraphs), the more likely the operation will never complete. Can you reproduce this behaviour?

Hi Ron,
I don't run into any problems trying to post messages to the Forum.
Maybe it's a browser related problem. I'm currently working on the Forum with Google Chrome.

I'll also check for possible database related problems, but those should have affected me, too.