If you are using MacOS, you may have encountered a dialog similar to this when attempting to open files that were downloaded from the internet:
(https://exiftool.org/forum/index.php?action=dlattach;topic=10809.0;attach=3466)
The reason for this is because MacOS adds a system XAttrQuarantine tag to files that you download. Using ExifTool, you may remove this tag, thus allowing you to open the file. The ExifTool command looks like this:
exiftool -xattrquarantine= FILE
After running this command on the file, you will be able to open it without being blocked by a dialog like above.
Specifically, for the above example dialog, you would run this command on the downloaded .dmg file before opening it:
exiftool -xattrquarantine= ExifTool-11.86.dmg
- Phil