Outlook Interop Exception

Question

Trying to automate Outlook as

Microsoft.Office.Interop.Outlook.Application myApp = new Microsoft.Office.Interop.Outlook.ApplicationClass();    
Microsoft.Office         


        

Answer 1

I had this problem too. I use Mobisynapse desktop app to update my Android Calendar and contacts. Using Office 2010 I decided to upgrade to Office 2016. After seeing it was a Office 365 product I uninstalled it. This caused the Registry to change the Office 2010 Primary Interop Assemblies to change from 32 bit to 64 bit. The Mobisynapse MB4Outlook started reporting sync error "Sync Failed". Mobisynapse – Moffice error 3/31/19 Sync Failed – there is a problem with outlook – on the desktop When I click on Auto Sync settings I get “Please update MB4Outlook add-in first” From where it is installed with your app.

Solution to this problem occurs when you try an Office365 product that is 64bit and have a 32 bit of office 2007-2013 installed. Step 1: uninstall Office xxxx primary interop assemblies. If the package is not found download from here. https://www.microsoft.com/en-US/Download/confirmation.aspx?id=3508 Install it. Step 2: run Office xxxx Install and select repair. Step 3: Reboot and it should fix the problem.