Just tried to post an item for sale and blank body of text happened. I can post an image through so wrote the advert, screenshot it and hosted & posted it. Seems to work for me:

https://www.locostbuilders.co.uk/forum/viewthread.php?tid=219300

Any news on getting this problem fixed?

I have a few items that might be of interest to members, but I can't post there.

...and today I started to get nags to make a donation to the running of this site... is this related to the problem? Although I started to get problems over a week ago.

Suspect its related to the hardware upgrades that happened recently.

If you want did of the parts you could just give them to me

I believe it has been fixed, obfripper found special characters (like a degree symbol) broke one of his posts, and _Luke, the one hiding in a dark server room somewhere, found a fix for this.
inevitably the pound £ character would appear in a for sale ad. hence forsale was the most affected.
I thank all involved for this resolution

It's definitely fixed - I've just posted an ad.

Thanks to whoever fixed it!