It appears with 2.8 having to specify aggregation by "All Records", instead of the defaulted all records aggregation with 2.7 and prior, files created with 2.7 containing aggregate blocks in DataManager without any fields specified will not always get aggregated when ran by 2.8 server.
I have been testing the 2.8 server running 2.7 files, the results are quite random....sometimes some aggregation blocks run properly and sometimes none of the aggregation blocks function.
Thanks for reporting this issue to us. We have now fixed this problem. The fix will be available in the next Omniscope 2.8 release (b1034), which should be available tomorrow.