screenshot
I create a new topic, and use an example from the [[mw:Manual:Math]] page.
The Preview works successfully.
When saved, the post currently displays as empty. (post #1 in the screenshot)
I then try to reply to that post, with identical content. That results in the long error message. (post #2 in screenshot.)
If I try to edit the original post #1, I get the long error message when I try to save it.
Full error message:
"Exception Caught: Unexpected end tag : a Unexpected end tag : a Unexpected end tag : span Unexpected end tag : script Unexpected end tag : button Unexpected end tag : form Unexpected end tag : div Unexpected end tag : div "
(Replicated at mediawiki, and beta.wmflabs.)
In some instances (and consistently on Enwiki), it won't let me Preview at all, and gives the error: "An error has occurred while processing HTML/wikitext conversion."
Use this, to test: <math>\alpha</math>
Version: unspecified
Severity: normal
Attached: