Why reports with aggregate functions (like singlescore, Trend, etc) are failing with error "Error processing request: null" and "java.lang.NullPointerException"? - Support and Troubleshooting

Why reports with aggregate functions (like singlescore, Trend, etc) are failing with error "Error processing request: null" and "java.lang.NullPointerException"? Description  Symptoms With the reports which are using "aggregate" function, while saving the new one or loading/running the existing one, system was throwing error "Error processing request: null" as shown in the below screenshot,

Looking into the session debug log would reveal following exception:

Node log has the same exception logged as below,

2018-07-11 16:27:52 (527) http-47 New transaction E32EA66C2D9B934020D2F911D6903C36 #161529 /xmlhttp.do 2018-07-11 16:27:52 (536) Default-thread-451 E32EA66C2D9B934020D2F911D6903C36 txid=3987f2a42ddb #161529 /xmlhttp.do Parameters ------------------------- sysparm_timer=1531319272529 sysparm_scope=global sysparm_processor=SingleScoreRunProcessor is_portal= sysparm_request_params={"sysparm_table":"sc_req_item","sysparm_aggregate":"COUNT","sysparm_sumfield":"assigned_to...","sysparm_query":"","sysparm_interactive_report":"","sysparm_report_drilldown":"","sysparm_report_id"...,"sysparm_list_ui_view":"","sysparm_decimal_precision":"2","sysparm_report_source_id":"","sysparm_is_report_source_filter_already_combined":true,"sysparm_show_zero":"true"} 2018-07-11 16:27:52 (589) Default-thread-451 E32EA66C2D9B934020D2F911D6903C36 txid=3987f2a42ddb SEVERE *** ERROR *** java.lang.NullPointerException java.lang.NullPointerException

2018-07-11 16:27:52 (591) Default-thread-451 E32EA66C2D9B934020D2F911D6903C36 txid=3987f2a42ddb *** End #161529 /xmlhttp.do Release Any supported release.

Cause Following are the possible problems which can throw "Error processing request: null" & NullPointerException, and cause issues with aggregate type reports.

PRB944384 - Saving report displays "ERROR: Error processing request: null" when sys_report.sumfield is greater than 40 characters

PRB1240032 - The single score report shows an error when the result number is 0

All these PRB's are fixed in Kingston release. If you are already on Kingston release but still running into the described issue, below one can be other possible causes for this issue.

Recent upgrade didn't go well as expected. You can verify this via checking below things,

System Diagnostics => Upgrade History ( Check whether the recent upgrade is recorded here) Navigate to "sys_properties.list" and check values of "glide.war" and "glide.war.assigned", both of them should point to the currently upgraded version. System Diagnostics => Stats => Stats ( the "Build name", "Build Tag" & "MID buildstamp" should match with the recently upgrade version) The upgrade issues can cause the described issue with Aggregate type reports.

Resolution If incorrect upgrade was the cause of the describe issue, Clone your affected instance from source instance and then perform upgrade again.

Additional Information Upgrade Procedure for Self-Hosted Instances

Upgrade Best Practices for Self-Hosted Customers

Reports

Single score report