Previously, quick reply would show the full post editor, but now only shows a small strip to post in rather than an actual editor. This only happened just today, I never previously had this problem...

Hi,

Can you please provide a screenshot of this issue, thank you.

Regards,
Sir chivas.

^ It seems to have been fixed now...this has happened once before in the past after switching themes (which I also did just now), so it's probably related to that. But it's been fixed now.