Salesforce Fact #878 | (already output) error in debug log
Have you encountered the error (already output) in the debug log? This error is encountered whenever the collection is not initialized or reinitialized properly in the code logic and it might lead to unexpected results. Reference: https://salesforce.stackexchange.com/questions/290468/to-know-more-about-already-output-in-logs Attached is an example screenshot.