Exchange 2013 Alert: "The A/V Edge service is misconfigured or isn't operating correctly"

After migrating from Lync to Skype For Business, we started getting SCOM Alerts for the A/V Edge Services on our Exchange servers.
Checking the Application Event Logs for UM events at that timestamp, I noticed Events ID's 1692 and 1438 for MSExchange Unified Messaging - UMCore.
It seems that Exchange was still communicating with an old Lync Edge rather than the new S4B Edge Pool.
Unfortunately the TechNet link in the SCOM alert doesn't tell you squat, except to check the Health Set. 
Luckily the Event 1438 tells you exactly what needs to be changed...I wish all events would be so kind :)

SCOM Alert Details:

Alert: {2}
Category: Custom
Time Raised: 3/25/2016 1:48:30 PM
State: New
Source: MBX-03 - UM.Protocol
Path: MBX-03.domain.com;MBX-03.domain.com
Last modified by: System
Last modified time: 3/25/2016 1:49:31 PM
Description: The A/V Edge service is misconfigured or isn't operating correctly
Knowledge: http://technet.microsoft.com/en-us/library/ms.exch.scom.UM.Protocol(EXCHG.150).aspx?v=15.0.1156.6

Event ID 1692:

Log Name:        Application
Source:              MSExchange Unified Messaging
Date:                  3/25/2016 1:48:30 PM
Event ID:           1692
Task Category:  UMCore
Level:                Warning
Keywords:         Classic
User:                  N/A
Computer:         MBX-03
Description:
The Microsoft Exchange Unified Messaging service couldn't establish a media channel with the current Lync Server Audio/Video Edge resources associated with LyncEdge.domain.com:5061. Diagnostic information: No diagnostic information is available.

Event ID 1438:

Log Name:       Application
Source:             MSExchange Unified Messaging
Date:                 3/25/2016 1:48:30 PM
Event ID:          1438
Task Category:  UMCore
Level:                Warning
Keywords:         Classic
User:                  N/A
Computer:         MBX-03.domain.com
Description:
The Microsoft Exchange Unified Messaging service on the Mailbox server has been configured to automatically use the Lync Server A/V Edge resources associated with LyncEdge.domain.com:5061'. Inbound and outbound calls involving remote users (located outside the enterprise) might be failing using the current Lync Server A/V Edge resources. To correct the issue, set the SIPAccessService property using the Set-UMService cmdlet. The Microsoft Exchange Unified Messaging  service will start using the Lync Server A/V Edge resources corresponding to the new value.

The Fix:

Fire up the Exchange Management Shell (EMS) and run:

 

Get-UMService | Select Name, Status, SIPAccessService | ft -AutoSize

Most likely your SIPAccessService field is blank, so we'll need add the new S4B Edge Pool in there.

Run the following cmdlet:

Get-UMService | Set-UMService -SIPAccessService Skype4BEdgePool.domain.com:5061​

**Note** Change Skype4BEdgePool.domain.com to your Skype For Business Edge Pool name.

 

Restart Unified Messing Service on each Exchange Mailbox Server.

 

No more annoying alerts!