Canvas does not allow drawing

[Daniele Buttarelli]

Hi,
using TDBRichViewEdit 1.9.24 sometimes I get an EInvalidOperation exception (Canvas does not allow drawing).
Unfortunately I cannot reproduce this error for debugging.
Can you help me?
Here's the callstack:

exception class : EInvalidOperation
exception message : Canvas does not allow drawing.

main thread ($ae8):
0048b01d +03d Teseo2.exe Graphics TCanvas.RequiredState
0048af1e +012 Teseo2.exe Graphics TCanvas.GetHandle
00adf41f +1bf Teseo2.exe RVStyle 2571 +58 TCustomRVFontInfo.Apply
00ae9966 +06a Teseo2.exe RVStyle 7212 +8 TRVStyle.ApplyStyle
00abefde +086 Teseo2.exe RVRVData 1106 +8 TRVFontInfoCacheFast.GetItems
00abef13 +017 Teseo2.exe RVRVData 1085 +2 TRVFontInfoCacheFast.Clear
00a765cf +00f Teseo2.exe RVClasses 93 +1 TRVList.Destroy
00404940 +008 Teseo2.exe System TObject.Free
00acece1 +011 Teseo2.exe CRVFData 7140 +2 TCustomRVFormattedData.DestroyFontInfoCache
00abeede +012 Teseo2.exe RVRVData 1067 +2 TRichViewRVData.DestroyFontInfoCache
00ac4ed0 +620 Teseo2.exe CRVFData 2503 +115 TCustomRVFormattedData.Format_
00a9ceaa +0be Teseo2.exe RVERVData 4393 +19 TRVEditRVData.Format_
00b0fe79 +039 Teseo2.exe RichView 1466 +4 TCustomRichView.Format_
00b0fcda +016 Teseo2.exe RichView 1153 +1 TCustomRichView.Format
00eaac46 +2a6 Teseo2.exe DBRV 844 +46 TDBRichViewEdit.DoLoadField
00eaaebb +15b Teseo2.exe DBRV 892 +18 TDBRichViewEdit.DataChange
0059b228 +018 Teseo2.exe DBCtrls TFieldDataLink.RecordChanged
004790f0 +004 Teseo2.exe DB TDataLink.DataSetChanged
004790aa +0be Teseo2.exe DB TDataLink.DataEvent
0047962d +03d Teseo2.exe DB TDataSource.NotifyLinkTypes
0047965e +01e Teseo2.exe DB TDataSource.NotifyDataLinks
0047968b +023 Teseo2.exe DB TDataSource.DataEvent
0047dd08 +0cc Teseo2.exe DB TDataSet.DataEvent
0058dbb8 +058 Teseo2.exe DBClient 1701 +10 TCustomClientDataSet.DataEvent
0047ddc5 +04d Teseo2.exe DB TDataSet.EnableControls

[Sergey Tkachenko]

Unfortunately, this version of TRichView is too old, so I cannot find a reason for this problem.

[giovani.erthal]

I already had this problem.

Maybe that will help.

Make sure you have a default printer set in Windows. If not, define one. If you already have it, change it.

I hope this helps.