I have converted a bunch of reports from VRW 2.x to DR 8.0 and in addition am using Michael Mullan's sub-class cDRReportMSSQL (DF19.1).

The reports run correctly, but clicking anywhere on the preview output area (not the scrollbar or the menu bar) gets the error: 'The report COM object for (object="oMain...oReport") does not have a window handle':

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At which point the Previewer becomes unresponsive (including the scrollbar, but not the menu bar, although not everything on that works properly) until closed.

Printing to the printer works OK.

What am I doing wrong?