"WARNING: Invalid order by field "instance.number": You can only order by the "Group By" field and/or the "Stacked" field" whren running a reportIssue When running a report, the following error is displayed at the top of a report, just below the filters: "WARNING: Invalid order by field "instance.number": You can only order by the "Group By" field and/or the "Stacked" field"CauseOne cause of the issue is the 'Sort by' value which is not matching the 'Group by' value.ResolutionReview the 'Sort by' value and the 'Group by' value and make sure they are matching. It's important to note that the 'Sort by' option does not support dot-walked fields as documented in the following documentation page at step 7: Create a bar report: "Add sort cannot be applied to dot-walked fields."