Events 1069/1564 DAG(exchange) Cluster Witness: File share witness resource ‘File Share Witness (\\)’ failed to arbitrate for the file share ‘\. Please ensure that file share ” exists and is accessible by the cluster

Make sure you do backups prior to doing any changes as  this solution may not be suitable for you or related to another problem  ;

Problem: Witness share is not available for your Dag System;

Solution: Ensure all your permissions are correctly set in your witness share and alternate witness ;

Run the following command to identify your witness configuration

1. Exchange Powershell command to get all witness shares

Get-DatabaseAvailabilityGroup -Identity "YOURDAGNAME" -Status | fl name,servers,witnessserver,witnessdirectory,alternatewitnessserver,alternatewitnessdirectory,operationalservers,primaryactivemanager,witnessshareinuse 

2. Connect to the Witness shares (Primary and secondary) that have the issue and Set the following permissions; Share and Ntfs must be in equal permissions and the cluster computer object must have full access + Exchange trusted subsystem ;

The account is easy to identify as the description shows as “Failover cluster virtual network name account”

Cluster Account in AD :

Permissions for Witness and alternate witness ( NTFS + SHARE MUST BE EQUAL )

3. Restart cluster service in the nodes and test if the witness is online;  if not working repeat the witness share creation again & restart the cluster;