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Exchange 2016 – Exchange Web Services Managed API 2.2 issues

There is a known issue that may be caused when Exchange Web Services Managed API 2.2 throws up events. Issues such as:

  • No free/busy info in scheduling assistant.
  • Out of office will not working on outlook as the user when click on it and wait for a couple of seconds(10sec – 30sec) the will receive the following message:

    “The automatic reply settings cannot be saved. The server may be unavailable, or your auto-reply message is larger than allowed by the server”

    And if user tries from OWA it will be working correctly.

Then if you go to exchange server and open event viewer you will find repeated warning event with event ID 5011 as following:

Log Name: System

Source: Microsoft-Windows-WAS

Date: **-**-2017 14:17:03

Event ID: 5011

Task Category: None

Level: Warning

Keywords: Classic

User: N/A

Computer: FQDN of Exchange Server


A process serving application pool ‘MSExchangeServicesAppPool’ suffered a fatal communication error with the Windows Process Activation Service. The process id was ‘36384’. The data field contains the error number.

Event Xml:

<Event xmlns=””>


<Provider Name=”Microsoft-Windows-WAS” Guid=”{524B5D04-133C-4A62-8362-64E8EDB9CE40}” EventSourceName=”WAS” />

<EventID Qualifiers=”32768″>5011</EventID>






<TimeCreated SystemTime=”2017-**-**T13:17:03.000000000Z” />


<Correlation />

<Execution ProcessID=”0″ ThreadID=”0″ />


<Computer>FQDN of Exchange Server</Computer>

<Security />



<Data Name=”AppPoolID”>MSExchangeServicesAppPool</Data>

<Data Name=”ProcessID”>36384</Data>




Then you should got to control panel and install Exchange Web Services Managed API 2.2 as following:

Then the user should work normally with all features and the event will stop appearing on the server event viewer.

Ratish Nair

Microsoft MVP | Office Servers and Services

Team @MSExchangeGuru

One Response to “Exchange 2016 – Exchange Web Services Managed API 2.2 issues”

  1. Monthly IT Newsletter – November 2017–January 2018 – Guy UC World Says:

    […] Exchange 2016 – Exchange Web Services Managed API 2.2 issues […]

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