I use zipmaster in a thread to compress/uncompress files. Recently, I encountered an 'Invalid Pointer Operation' error during compress. There are several error message boxes popup, but the files were compress correctly. Here are the code I'm using to create the zip object: zip := TZipMaster.Create(nil); zip.ZipFileName := 'test.zip' zip.AddOptions := [AddDirNames, AddSeparateDirs]; zip.ExtrOptions := [ExtrOverWrite, ExtrDirNames, ExtrForceDirs]; zip.UseDirOnlyEntries := True; zip.Unattended := True; zip.Verbose := False; zip.Trace := False; zip.NotMainThread := True; zip.OnItemProgress := zipItemProgress; BTW, I'm using FastMM and ZIPMaster 1.79.08.02 If anybody encountered such problem before, I'd very appreciate to know the solution. Thank you! Lewis ----------- To unsubscribe from this list, send an empty e-mail message to: delphizip-request@xxxxxxxxxxxxx and put the word unsubscribe in the subject.