I had written a long message then lost it so excuse me if I abbreviate here in case it happens again. I'll add more details later in a follow-up if needed.

I run the same survey every year which pulls the users out of an LDAP database on the same Linux server (ie. Limesurvey's localhost). This year although the LDAP server is running fine (tested eg. with slapcat) suddenly LimeSurvey complains that it can't upload my LDAP query. There is no further information about why. How would I go about debugging this?