@matthiasmullie and I were both able to reply to a post and edit. I also previewed.

We think another script may be interfering, since @Quiddity says a bare account works fine. But there could also be some intermittent failure.

It seems to be a gadget issue?
If I enable both of these 2 at https://www.mediawiki.org/wiki/Special:Preferences#mw-prefsection-gadgets

• Site: General utilities needed by the templates and portals of this wiki.
• HotCat, easily add / remove / change a category on a page, with name suggestion [example]

then things don't work at all.

I've made some screenshots about this:

First one is the HTML/wikitext conversion error: https://www.mediawiki.org/wiki/File:Phab-T86064_First_try.png

I tried with several syntaxes, i.e :meta:, :w:, meta:, and even with the whole URL and just simple brackets, all the same.

Second one is about the unexpected end tag: https://www.mediawiki.org/wiki/File:Phab-T86064_second_try.png

I've got no chance to save this, so I just created the new post.

The only non-standard gadget I've activated is "Dot syntax highlighter" and all beta stuff besides hovercards.

Can you paste (see https://phabricator.wikimedia.org/paste/create/ ) the exact content you tried to save?

Something like this: https://phabricator.wikimedia.org/P199 ?
It was used for both, the first one was preview, the second one send.

Edith says:
The original has :mw: in front of the link.