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've been stumped by this problem for days. This worked for me:

I just realized that Outlook 2013 is 64 bit... And my C# app had in Project Properties -> Build "Any CPU" as platform target and a check-mark in "Prefer 32-bit".

I changed the Platform target to x64 and it worked!

Answer 2

   //DECLARE
    Microsoft.Office.Interop.Outlook.Application app = null;
    Microsoft.Office.Interop.Outlook.NameSpace ns = null;

  //INITIALISE
    app = new Microsoft.Office.Interop.Outlook.Application();
    ns = app.Session;

Answer 3

Same error exactly in the same place:

Outlook.NameSpace ns = application.GetNamespace("MAPI");

I have a Win 10 and Office 365 - both 64 bits - with no previous Office installation; I tried several solutions above and did too Office quick repair, to no avail.
After running a Office online repair it functions like a charm.

Answer 4

For me removing 9.5 entry from this registry works:

HKEY_CLASSES_ROOT\TypeLib\{00062FFF-0000-0000-C000-000000000046}

Answer 5

The exception looks quite obvious, this should work

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

you just can't get a cast exception with that line above.

Answer 6

The fix of the 9.5 version didn't work for me, as there was no excessive 9.5 field.

In my case, the problem was that when I downgraded to Outlook 2010 I have modified the installation location (i.e. not in the default ProgramFiles folder). However, windows didn’t update accordingly the value in ‘HKEY_CLASSES_ROOT\TypeLib{00062FFF-0000-0000-C000-000000000046}\9.4\0\win64’.

After manually updating the value and pointing it to the right location, the problem was resolved.