Troubleshooting Exchange Mountability check errors "Jet returned error code -528" (4036378)

Mountability checks are failing for Exchange Protected Machine. It is failing with the
error "Failed Checks Count" under Recover Points and is red on the databases. The
DAG is staying green though and Summary states that it has been taking snapshots and
checksum check is successful.

Error opening database. Jet returned error code -528, Error closing database,Jet
returned error code -528, Database cannot be mounted.

Replay.Core.Contracts.Exchange.MountabilityChecks.MountabilityCheckFailedException: Mail store
'D:\ExchangeDB\CS-Database\CS-Database.edb' is not mountable. Error: 'Error opening database.
Jet returned error code -528, Error closing database, Error opening database. Jet returned error
code -528, Database cannot be mounted'

Here are the steps to troubleshoot the Mountability check failures. We need the outcome for each steps to reveal the root cause of the problem.

Please perform next troubleshooting steps one by one to address the Mountability error issue:

Step 1: Modify Replay Engine IP settings
1. Go to the Core Console-> Configuration ->Replay Engine Configuration.
2. Increase Read and Write Timeouts to the 1:00:00.
3. Set Replay Engine IP to 127.0.0.1
4. Force the Mountability check and see the result. In case of fail proceed to next step.

Step 2: Extend drivers timeouts
1. Ensure all mounts have been dismounted.
2. Shut down Core service.
3. Stop the AAVDisk and AAVStor drivers. (sc stop aavdisk, sc stop aavstor)
4.Create key AsyncNetworkTimeout REG_DWORD in HKLM\System\CurrentControlSet\Services\AAVdisk\Parameters\AsyncNetworkTimeout and set the value to 600000
5. Extend the AAVDisk and AAVStor driver NetworkTimeout to 600000 (dec). The values are located at HKLM\SYSTEM\CurrentControlSet\Services\AAVdisk\Parameters\ and HKLM\SYSTEM\CurrentControlSet\Services\"driver name"\Parameters\
- Start the AAVDisk and AAVStor drivers. (sc start aavdisk, sc start aavstor)
- If the drivers will start, then start Core service and resume transfers.
- If the drivers won't start/stop, then reboot the core server.

6. Suspend all transfers and active jobs
7. Force the Mountability check and see the result.

In case, Mountability check continues to fail, proceed to the next step.

Step 3: Force the Mountability check for the first RP (base). With any result proceed to next step.

Step 4: Mount RP for which mountability failed and perform the eseutil /g command for the DBs. .

Here is a reference link on how to perform eseutil commands, should you need - http://msexchangeguru.com/2009/07/12/exchange-database-recovery-using-eseutil-commands/

Step 5: Run 'ESEUTIL /ML' command on the Agent machine for the log file of any problematic DBs. You can find an example here: http://www.msexchange.org/articles-tutorials/exchange-server-2010/management-administration/eseutil-part1.html.

run from cmd from the C:\ directory
fsutil fsinfo ntfsinfo {DB disk} (D:\ in case of troubleshooting D:\ExchangeDB\IT-Database\IT-Database.edb dbs)
fsutil fsinfo ntfsinfo {repository location disk}

With any result, proceed to next step.

Step 6: If its possible dismount one of the problematic DBs on the Agent machine and force eseutil /g command for it. In case if useutil finish successfully proceed to next step.

Step 7: Force a new Base Image and force a Mountability check.