This file could not be opened for writing...(MacOS Error code: -54)

[musique]

Among other backup schemes I use TimeMachine to backup to a NAS that is located near my workspace and is somewhat noisy. I looked into changing the interval between TM backups from 60 minutes to something larger, like, say 120 or 180 minutes.

I've found some information that seems to say that the interval can be changed in:
System/Library/LaunchDaemons/com.apple.backupd-auto.plist

This plist file has the interval set to 3600, the number of seconds in an hour. Using BBEdit I changed the interval to 9000. When I went to save the file though I got this message:

This file could not be opened for writing, probably because it is in use by another application (MacOS Error code: -54)​

Automatic TimeMachine backup is turned off. I'm the only user on this MBP (with 4 USB-C/Thunderbolt 3 ports) running macOS Sierra (10.12.6).

Any idea why I'm getting the message and how to fix it would be appreciated. Thank you.

 

[jbarley]

I use "TimeMachineEditor", free, very configurable, easy to use, and works without issues.
https://www.macupdate.com/app/mac/26704/timemachineeditor

 

[BrianBaughn]

You might be able to copy the file to your desktop, edit the copy, and then overwrite the system files with the copy. But TimeMachineEditor is the way you should probably go.

 

[musique]

Thanks to you both. "TimeMachineEditor" seems to be working like a charm.