Set the DAG share witness prompt "Access denied" error resolution

Problem Description:
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The following error occurred while setting up the DAG shared witness server:
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Microsoft Exchange Warning
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The following warning appears when saving changes:

Set-databaseavailabilitygroup

is complete

Warning:

The specified witness server Dc.doubioa.ren is not an Exchange server, or is not part of the Exchange Server security group.

Warning:

Insufficient permissions to access the witness server "Dc.doubioa.ren" Network file share. Before you correct this problem, the database Availability group may increase the vulnerability that caused the failure. Please retry the operation using Get database availability group. Error: Access denied.

Warning:

The command completed successfully, but no settings for "DAG-01" were modified.
Reason:
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If the specified witness server is not an Exchange 2010 server, you must add the Universal Security group for the Exchange trusted subsystem to the local Administrators group on the witness before you create the DAG. These security permissions are required to ensure that Exchange can create and share directories on the witness server as needed.
Workaround:
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Add Exchange trusted subsystem to the Administrator group that is local to the witness server.

Set the DAG share witness prompt "Access denied" error resolution