Error starting MS Outlook - Problem Event Name CLR20R3

  • Thread starter Sydney Taylor
  • Start date Views 10,857

Sydney Taylor

Problem signature:

Problem Event Name: CLR20r3

Problem Signature 01: outlook.exe

Problem Signature 02: 14.0.4760.1000

Problem Signature 03: 4ba8fefd

Problem Signature 04: Mainsoft.Harmony.AddIn

Problem Signature 05:

Problem Signature 06: 4c90f159

Problem Signature 07: 137

Problem Signature 08: f

Problem Signature 09: System.InvalidCastException

OS Version: 6.1.7600.

Locale ID: 1033

Diane Poremsky

Senior Member
Outlook version
Outlook 2016 32 bit
Email Account
Office 365 Exchange
Does outlook start in safe mode or if you disable the " Mainsoft.Harmony.AddIn" addin?

To start in safe mode: Close Outlook. Hold Ctrl as you click on the Outlook icon to open in safe mode.

To disable addins: File, Options, Addins. Click Go at the bottom of the page and uncheck the addin - it will probably be listed with a 'friendly name' so you'll need to figure out which one it is.