I'm on SP2016 On-Prem August 2016 CU...

I got the following error message on timer job 'User Profile Service Proxy - Feed Cache Repopulation Job':

Unexpected exception in FeedCacheService.IsRepopulationNeeded: Failed to Decrypt data

But only on one Search Server?!

What I've done:

  • Redeploy distributed cache
  • Change timeout settings
  • added the application pool account to the UPA
  • what is status of the DC? and how many servers it is running?
    – Waqas Sarwar MVP
    Aug 24, 2016 at 12:48
  • 3 server... service status: UP on all 3 servers...
    – domsen123
    Aug 24, 2016 at 13:05

1 Answer 1


I had the same "Failed to Decrypt data" issue with SharePoint 2016. After opening a support case with Microsoft we found that the server was unable to decrypt the DistributedCache key within the registry here:

HKLM\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\16.0\Secure\Credentials

The Solution was to rename the "Credentials" key then reboot the machine. After the reboot, the "Credentials" key will be automatically recreated. Confirm that the correct permissions are set for the "Credentials" key after the reboot:

The permissions should be: WSS_WPG – Read, WSS_ADMIN_WPG - full control

If the permissions were not correct you, you will need to correct them and then reboot again.

I can confirm that after this I no longer received any Event ID: 6398 Errors in the Application event log.

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