# error/qtype stack/exceptionmessage

<div class="mw-content-ltr mw-parser-output" dir="ltr" id="bkmrk-you-may-get-the-stac" lang="en">You may get the *stack\_cas\_connection: maxima launch script \[dataroot\]/stack/maxima.bat does not exist.* error if you are trying to create a STACK question but you do not have Maxima installed.

See [STACK installation instructions](/503/en/STACK_installation_instructions "STACK installation instructions")

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<small>Source: [docs.moodle.org/503/en/error/qtype stack/exceptionmessage](https://docs.moodle.org/503/en/error/qtype%20stack/exceptionmessage) — MoodleDocs (GPL) · Imported 2026-11-10.</small>