In Microsoft Office, you may encounter a random runtime error with Enterprise Connect plugin when you launch any Office application.   Custom UI Runtime Error in Enterprise Connect Error found in Custom UI XML of “Enterprise Connect”:

Line: Column: Error Code: Unknown Office control ID   To fix, disable the Enterprise Connection office Add-in...

If you try to open Citrix Receiver multiple times, you will receive the following error.  

Unable to launch your application. Contact your help desk and provide them with the following information: Cannot open the Citrix Receiver.

Did you just import or build a contact list into your Microsoft Outlook contacts and you received a message about more contacts being supported by a previous version of Outlook? Here is the message you may receive.

  This contact group contains more members than supported when using Microsoft Outlook 2007 Service Pack 1...

If you are using Microsoft Lync, you may receive a prompt about Lync attempting to connect to a certificate upon signing in.   Lync is attempting to connect to: Autodiscover-s.outlook.com

CERTIFICATE DETAILS Outlook.com Issued by: DigiCert Cloud Services CA-1 Owned By (Subject): Outlook.com The connection to the server is encrypted. Lync cannot verify that...

You may receive an error message in Microsoft Outlook using the CRM plugin.

  The system could not log you on. This could be because your user record or the business unit you belong to has been disabled in Microsoft Dynamics CRM.   This error is due to your CRM account being deactivated or...