MAPI solutions do not work because Outlook.exe is not properly registered under the \App Paths key in the Registry
Original KB number: 2698523
Symptoms
If you are using a custom MAPI solution (for example, an Outlook add-in), the solution may not work because Outlook.exe is not properly registered in the Windows registry.
Note
The actual problem you experience with the custom solution depends on how it uses the Outlook.exe registration information.
Cause
This problem can occur if Outlook.exe is not registered correctly under the following keys in the Windows registry:
32-bit versions of Windows
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths
64-bit versions of Windows
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\App Paths
If Outlook.exe is properly registered, you will find an \Outlook.exe subkey under the above key, and under the \Outlook.exe subkey you will find a string value called Path whose data references the correct path to Outlook.exe on your computer. The following figure shows the correct Outlook.exe registration on a 32-bit version of Windows.
Note
The path to Outlook.exe on your computer may vary from the above figure if you installed Office in a non-default location.
Resolution
To resolve this problem, repair your installation of Office.
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