496 - Unable to perform an Integrity Check while a mirror is in progress

Symptom

The following error is seen in the StorageServer log when trying to perform a Integrity Check:
Info: CLIENT\ACCOUNT -  Integrity: Quick Integrity Check with Fixes Initiated
Error: CLIENT\ACCOUNT -  Integrity: Unable to perform an Integrity Check while a mirror is in progress 

Cause

Unless the account has completed a mirror under certain circumstances, the MS will add the DataindexPending=true flag to the LocalSettings.txt file of this account. While DataIndexPending=true, the Integrity Check process will not be allowed.

Solution

1. Browse to the GUID for this account on the StorageServer, eg: C:\ProgramData\Attix5 Pro\SS_Service\Data\<AccountGUID>.
2. Edit the file LocalSettings.txt. 
3. Change DataIndexPending=true to false (or completely remove DataIndexPending=true from the text file).
4. Save the changes. 
5. Run a Quick Integrity Check with Fixes.