I've recently disabled the cached Exchange mode for our users and switched them to online mode. Although I made this change in the Group Policy Object (GPO), we're still facing a data file error that pop-ups with the message 'The set of folders cannot be opened.' The error goes away when I click 'OK,' and Outlook loads just fine in online mode. I'm trying to figure out where this lingering reference to the data file is coming from. Any ideas?
1 Answer
It seems likely that Outlook is still referencing an old OST data file from when cached mode was enabled. This can happen if the existing Outlook profile or local settings still point to the old data. I recommend trying to recreate the Outlook profile and possibly removing any lingering OST files to resolve the issue.

I've already reset the profile in the registry, but the problem persists. I found some remnants in HKEY_USERSS-1-xxxxxxxSoftwareMicrosoftOffice16.0OutlookProfiles.