For anyone who's had the same problem: the culprit in my case was font-lock-maximum-decoration, which I had customized to level 1. I don't know how and where these decoration levels are defined, but the ones associated with latex-mode and LaTeX-mode seem to have been changed recently.
Setting it to level 2 restores the syntax colouring; I just erased that customization and left the default ("t", max decoration). Cheers, Luca On 250826 06:40, Luca wrote:
Hi everyone (and Tassilo, thank you for the great tip about crdt.el), I just wanted to inquire if anyone here has also had syntax colouring disappearing almost completely in AUCTeX (see first enclosed pic). I don't think it's an AUCTeX bug, because it works fine calling Emacs with no init (`-Q` option) and then loading AUCTeX. But it's only happening in AUCTeX buffers. font-lock and modus-themes don't seem to be the problem either. But something in the latest updates of packages did this. While I'm debugging, I just wanted to inquire whether anyone here has also experienced this and any insight they might have. Cheers, Luca