Aggregating is only supported in grids with a database source 5.17
After converting an app from 5.15 to 5.17, the following errors appear on all the aggregate functions in a grid: Aggregating is only supported in grids with a database source Nothing is written about this in the release notes. Do I need all the data sources types from association to database? This would imply that the aggregation only calculates over data from the database, it will skip the not-yet-stored data.
Aggregates never worked for other data sources than database because they are computed by using SQL queries. They were inadvertently allowed for other data sources and we fixed that in 5.17. I have added it to the release notes.