Veeam-MS Exchange Writer Retryable Error

It is very common to encounter the following error message in Veeam Backup when backuping Microsoft Exchange Server

6/18/2018 8:37:38 PM :: VSS: Backup job failed.
Cannot notify writers about the 'BACKUP FINISH' event.
A VSS critical writer has failed. Writer name: [Microsoft Exchange Writer]. Class ID: [{76fe1ac4-15f7-4bcd-987e-8e1acb462fb7}]. Instance ID: [{5e2cc993-8c98-4f33-98b6-9697ceaecbaf}]. Writer's state: [VSS_WS_FAILED_AT_BACKUP_COMPLETE]. Error code: [0x800423f3]. 

If you enter "vssadmin list writers", you will see the Microsoft Exchange Writer is in Retryable Error

Writer name: 'Microsoft Exchange Writer'
Writer Id: {76fe1ac4-15f7-4bcd-987e-8e1acb462fb7}
Writer Instance Id: {5e2cc993-8c98-4f33-98b6-9697ceaecbaf}
State: [12] Failed
Last error: Retryable error

Please refer to the following steps on how to resolve it without rebooting Exchange Server
1. Move all the Active Mailbox Databases to another Exhange 2013 Server (Assuming you have DAG Cluster configured)
2. Restart Microsoft Exchange Information Store & MS Exchange Mailbox Replication Services

$ActiveServer="EX01"

#Move Mailbox DB
#Good Availability: (when selecting Good Availability, the database will mount automatically as long as you have a copy queue length less than or equal to 6

Move-ActiveMailboxDatabase DB1 -ActivateOnServer $ActiveServer  -MountDialOverride:GoodAvailability -Verbose
Move-ActiveMailboxDatabase DB2 -ActivateOnServer $ActiveServer  -MountDialOverride:GoodAvailability -Verbose

#Restart the following Exchange Services
Restart-Service -Name MSExchangeIS
Restart-Service -Name MSExchangeMailboxReplication 

1. Microsoft Exchange Writer should show no error if you check again using “vssadmin list writers”
2. You will have to schedule to reboot your Exchange 2013 Server if the steps not helps