Unable to change EXIF date

[Kucera]

I am using the 'Modify EXIF date and time' tool to set the date of  some scanned files of old photos to the date the pictures were taken back in 1958.

Out of 417 files, 6 refuse to accept the new date, showing instead the date of the scan.

When I attempted to change the dates by writing it directly in the Metadata panel, it would not take it, either.

If I try to delete any of these 6 files, it tells me:

"The file could not be deleted. Make sure that the file is not write-protected, not currently in use and that you have sufficient privileges to delete files."

That, however, is not the case, I made sure that there is no write protection, using a file manager, as well as the  command line, as well as the shield icon in iMatch.

Next I set the created and modified times to year 1958 in another program, and re-scanned the folder - no luck, iMatch still stubbornly sticks to 2017.

Closed iMatch, got clean diagnostics, compacted and optimized.

Outside iMatch made a copy of one of these files to an "unwatched" drive and changed the original and modified dates to 1958 there. When I brought that directory into iMatch - it still showed 2017 as the date in iMatch!!!

What is happening, and is there some iMatch setting that I am unaware of? Attached is one of those files.
Best regards Emil

[Mario]

This file contains no EXIF record. Only XMP metadata.
Using the Modify EXiF Date & Time command is thus not needed and of course cannot work.

I changed the date and time of this file successfully in the Metadata Panel (using the Default layout). After writing back the data, I checked the XMP data in the file in ExifTool. The data is correct and shows the date and time I have entered in the metadata panel. Looks good to me.

Note: IMatch by default does not create EXIF metadata in files, it only updates existing EXIF data.
For files without EXIF data created by the camera or scanner, this is the recommended workflow.

If you really need to create EXIF data for this file, you can do that using ExifTool on the command line (copying the existing XMP data into EXIF). See the ExifTool Web Site / FAQ for details.

I did that for testing. The date and time I had entered in IMatch and written to the XMP record was copied to the EXIF data.
When I now change the date and time again in IMatch (MD panel), IMatch updates both XMP and EXIF (because there is now an EXIF record in the file).

"The file could not be deleted. Make sure that the file is not write-protected, not currently in use and that you have sufficient privileges to delete files."

I think this is caused by Windows WIC / DirectX.
I could reproduce that when I kept the Quick Preview Panel open. When I tried to update / change the file while it was loaded into the panel, ExifTool failed. It seems that WIC/Directx does not like the file format and causes a lock on the file. This is rare but can happen. In such cases it helps to close the Quick Preview Panel while you are trying to manipulate the file.

[Kukn]

[German]
Hallo,
als kleiner Tipp von mir, bei solchen "störischen" Dateien lösche ich mit ExifTool 'Modify>Remove metadata' die Metadaten und schreibe mit iMatch einen 'sauberen' Metadatensatz zurück in die Datei (dann stimmt das mit dem Datum auch wieder).
Grüße von Kay

[Kucera]

Thank you, Mario, und Kay,
         The simplest way indeed was to close the preview panel, and the cleanup of metadata via exiftool is also a neat tip, vielen Dank.
And, since "there are more ways than one to skin a cat" - another, albeit very non-elegant workaround that I stumbled upon (in desperation ) was to edit the file in some way, for example, re-sizing or cropping outside iMatch and re scanning the directory. Thanks to your explanations I now understand that that created some exif data to be changed.
Many thanks and regards from Canada 
Emil