The sequence that made this error to could have been the following:
1. a Delphi form has been opened with a recent TVideoGrabber component and saved (.dfm and .pas). This has added an inititialization of the “PropertyName” property in the .dfm.
2. then, an older version of TVideoGrabber has been reinstalled in Delphi (instead of the recent one)
3. the Delphi form has been reopened with the older TVideoGrabber component
At this point the problem is that the .dfm contains the initialization of the property “PropertyName”, that did not exist in the older TVideoGrabber component being currently installed.
To go on working with the older TVideoGrabber version, the fix is quite simple : edit the .dfm, either with a text editor, either from Delphi (right-click on the form -> “View as Text”), and delete the line that contains “PropertyName”, then save the .dfm (in Delphi right-click “View as Form” to go back to the normal mode)
Note: if the TVideoGrabber component installed in Delphi has not been downgraded , the problem could be a mix of the TVidGrab.* and VidGrab.* bpl, dcp and dcu files. In this case scan the Delphi paths and project path for TVidGrab.* and VidGrab.* files, and move to a backup folder of the files having an older date/time than the date/time of the TVideoGrabber version you are expecting to use.