Error Message - Opportunity Trigger

I'm getting the following error when I try to update an opportunity in my instance - Does anyone know how to fix it?  I can't update any of the opportunity details.  TY

dlrs_OpportunityTrigger: execution of AfterUpdate caused by: System.SObjectException: Invalid field Contact for Opportunity (dlrs) Trigger.dlrs_OpportunityTrigger: line 7, column 1