I use MS Exchange Server 2016

Why are you running business-class Server on a consumer-class Alienware computer?

At this point, I suggest you restore from backup or contact Microsoft for assistance. 

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Unfortunately without any error codes it is difficult to provide any kind of solution, so if I am understanding correctly when you are attempting to mount a database on your server you could receive multiple different errors, for instance you could receive. An internal processing error has occurred, Try restarting the Exchange System Manager or the Microsoft Exchange Information Store service, or both.
ID no: c1041724
Exchange System Manager.
Additionally, the events may be logged in the Application log. 
Please provide error or errors listed, and I would be happy to try to assist you further.

AWCarter

But in case nothing can't assist you, take a look at following recovery edb

Moreover this article is too very helpful, read it - https://community.spiceworks.com/how_to/2217-repairing-a-corrupt-or-dirty-exchange-database

Here is detailed guide: http://www.slipstick.com/problems/pst-repair/convert-an-exchange-offline-file-ost-to-a-personal-file-pst/

Restore Exchange Account

If you deleted the Exchange account, you may be able to recover the account if your operating system supports system restore and you only recently deleted the account. If too much time has passed you are less likely to have a restore point available.

1. Open the system restore application. In Vista it is at Start Menu, Programs, Accessories, System Tools.

Or enter %systemroot%\system32\rstrui.exe in Start search field or Start menu, Run.

2. Pick a date just before the profile was deleted.

When Windows restarts the account will be back and you can move or export the contents of the OST to a PST. Then either delete the account or run restore again to return to the point made before the restore.