Add string attribute to Grouped by TableView fails

[MaartenHilferink]

Case: Open HestiaRun
go to /Invoer/RuimtelijkeData/OSM/Prepare_SourceData/Drenthe/Read_Roads_shp/oneway
Ctrl-D
Group by one way
Add fclass column

[MaartenHilferink]

Apparently, applying the aggregation function resulted in a freaky calculation rule:

'['+
String(min(/Invoer/RuimtelijkeData/OSM/Prepare_SourceData/Drenthe/Read_Roads_shp/fclass, ../GroupBy/per_Row))+'...'+
String(max(/Invoer/RuimtelijkeData/OSM/Prepare_SourceData/Drenthe/Read_Roads_shp/fclass, ../GroupBy/per_Row))
+']'

[MaartenHilferink]

When entering /Desktops/Default/View0/Contents/DataItemColumn1/Aggr in the address bar,
I could see it in the DetailPage with:

However, it did not appear in the TreeView.

Furthermore, /Desktops/Default/View0/Contents/DataItemColumn2/Aggr does not exist, apparently its creation was aborted by handling string before context was set.

Furtherfurthermore, when here and undo-ing the TableView aggregation" and then closing the tableview:
Access violation at address 0x00000042, but not reproducible.

Context: issue arose when looking for test data for #574

[MaartenHilferink]

Stack at first insert:

[MaartenHilferink]