Please make a process monitor log and we'll see if it indicates why the config file can't be updated from Opus:
In this case, to ensure the right things get logged:
- Start logging as per the linked post.
- Toggle the Apply checkbox in the metadata panel.
- Wait 45 seconds.
- Save the log as per the linked post.
The 45 second wait is because the config change is not saved immediately, in case other changes are made soon after it and can be batched together.
It might also be interesting to check what the Modified date on this file is:
C:\Users\<username>\AppData\Roaming\GPSoftware\Directory Opus\ConfigFiles\prefs.oxc
That would tell you the last time Opus was able to update its main config file. The date/time might help if it coincides with when something was updated/installed.
If file permissions aren't the issue, sometimes antivirus is. We've also heard of cases where the Windows Search Indexer gets stuck in an endless loop on XML files, which could be what's happening.