Can't edit the code list categories in "closer_audit" instrument

[beckyoldroyd]

From CA: when trying to edit the code list categories in this instrument https://closer-archivist.herokuapp.com/instruments/closer_audit_old/, the screen goes blank.

There are no issues when editing other constructs in this instrument, and I can't replicate the issue in other questionnaires on the main or staging, so it seems to be specific to this questionnaire.

We have a workaround (exported the XML from Archivist and re-imported it, and now we can edit the code list categories https://closer-archivist.herokuapp.com/instruments/closer_audit) but thought it's worth flagging in case you're able to figure out why this happened and prevent it from happening to other questionnaires.