.MOV files will not play after full Backup with Acronis 2018 to local HD

After backing up macOS 10.11.3 -  .MOV files will not play. Backup was with Acronis 2018 to local HD.

OS reports "Cannot Play Video" Photos cannot play this video because it uses an unsupported format."

The OS was not restored, only backed up. macOS reported after backup - had to 'Restore' photo library

Other format files (e.g. .mp4) play OK. .MOV files OK on my iPhone iOS 11.2.6

How can I ?? these .MOV files to play?
MARSPATHRetired EE/Computers/ITAsked:
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Dr. KlahnPrincipal Software EngineerCommented:
It sounds like Acronis corrupted either or both of:

a) the Quicktime video subsystem

If that is the case, you may be able to repair the damage.

b) at least part of the disk -- "macOS reported after backup - had to 'Restore' photo library" -- and the MOV files may only be the tip of an iceberg.

If that is the case, then I'm not sure that there is anything that can be done other than restore the system drive from a previous full image backup that was not made with Acronis.

Differential diagnosis:  Put the possibly-damaged files on a USB flash drive, take them to a PC, and there run the GSpot Codec Information Tool on the files.  See what it reports about the format, the codec, the encoding type, etc.  All the information displayed by GSpot should make sense, with none of it "unidentifiable" or "nonsense".  See the example below for GSpot examining an uncorrupted .MOV file.

 GSpot examining a MOV
If the files are uncorrupt, then it's probably Quicktime that has been damaged.  Note that even if this is the case, and you can repair it, there may still be other undiscovered issues lurking.

(Yet another reason why I will never, ever use Acronis again.)

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MARSPATHRetired EE/Computers/ITAuthor Commented:
Thanks (again) for your help. Restoring these ,MOV files is not an issue. I use Time Machine and iCloud as other backups of same data.

As these are photos/movies of my family (7 generations!), I have multiple backups: on another Mac, Time Machine and SmugMug. In addition, most of the oldest (1930's +) movies with my help, made their way to DVD. What I do with these files seen here... ijim.smugmug.com

Thanks for the tip about the GSpot Codec Information Tool. And yes, I have Macs and PCs on my LAN.

(Yet another reason why I will never, ever use Acronis again.) - This troubles me...
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