## Problem
Using mathpix-markdown-it with a custom code-block language (e.g. jldoctest) threw "Could not find the language 'jldoctest', did you forget to load/include a language module?" because the bundled highlighter only knew registered languages and errored on unknown ones. Typing a language name character by character also logged an error per keystroke.
## Verified fix
Upgrade to mathpix-markdown-it@1.2.6 (the custom-language fix landed in 1.2.5 via PR #259, with the follow-up per-keystroke console error fixed in 1.2.6 via PR #263). The reporter confirmed both fixes. After upgrading, unknown languages no longer spam console errors. Source: https://github.com/Mathpix/mathpix-markdown-it/issues/252