Evidence: <Where><Geq> on ID at 5495 (the newest item id 5500 less 5), grouping on LVChoice then LVNumber then LVDate with all three unindexed. The counter spelling was tried rather than assumed: Type="Counter": HTTP 200, SERVED (6 row(s)), so Type="Counter" is what answered. collapsed HTTP 500 returned 0 row(s) against a RowLimit of 100, labels {"LVChoice":[],"LVNumber":[],"LVDate":[]}, grouping markers [], dimensions honoured 0 of 3 on the collapsed rows ([]) and 0 of 3 on the expanded rows ([]), first row null; expanded HTTP 500 returned 0 row(s); the same query with no <GroupBy> returned HTTP 200 with 6 row(s); ViewXml <View><Query><Where><Geq><FieldRef Name="ID"/><Value Type="Counter">5495</Value></Geq></Where><GroupBy Collapse="TRUE"><FieldRef Name="LVChoice"/><FieldRef Name="LVNumber"/><FieldRef Name="LVDate"/></GroupBy></Query><ViewFields><FieldRef Name="FileLeafRef"/><FieldRef Name="LVChoice"/><FieldRef Name="LVNumber"/><FieldRe; collapsed body {"odata.error":{"code":"-2147467259, Microsoft.SharePoint.SPException","message":{"lang":"en-US","value":"Cannot complete this action.\n\nPlease try again."}}}. The three-FieldRef shape was not honoured even over a handful of rows, so a refusal of the same shape at full size cannot be attributed to the threshold: it may be the shape. Read the collapsed body above before reading anything below it.