After update to full crystal 2008 (12.0) some programm return this error. Windows program with Crystal Preview (All Report is on the preview before print).
We do all :
Registry Key set to -1
Create the report on the page load
Close and dispose the report on the FormClosed
Dispose the form with the preview
Use the GC.Collect after each Dispose of the form.
But some time we have this issue, is verry frustrating in version 10 we do notting and all work's good for year's.
Do your have property for returning the count of the engine about the number of reports in memory or property to hav access to the list of the report in the engine.