Office x64 Add-in issue

Jul 24, 2011 at 10:22 PM


Great work at all!

I tried to run your add-in examples using VS2010 on win7x64, Office 2010x64 but I didn't get it up and running.

I Added some MessageBoxes to the source and it seams like the IDTExtensibility2.OnConnection handler is never called.

I also tried to set the build platform target to x64 (from "Any CPU") to make it work.

Any ideas?

I already read the existing post on that issue but could not find a solution!


Jul 24, 2011 at 10:30 PM

please check out the registry key: Sofware\Office\OfficeApp\YourAddin
all keys are created?
what happens with LoadBehaviour after start?


Jul 25, 2011 at 3:00 PM

I tried again using the original setup. (any cpu)

RegKeys are added, but LoadBehaviour is set to 2.

I did also try to sign the assembly, turn off my antivirus software, ...

Any further ideas?



Jul 25, 2011 at 3:20 PM

hello wolfgang,

addins for x64 application must be compiled as x64

i'm not an expert with all office 2010 applications. whats your app?
some apps has explicitly security settings for extension/addins.

my test scenario in a virtual machine with win7x64 and excel x64 works fine.
but i dont know i have made changes in security settings...
i will take a look at home (@work currently)


Jul 28, 2011 at 5:47 PM

Hi Sebastian!

It works.. but i still don't really know what the problem was. Maybe the registry cleanup helped me out?

I created a new vs2010 solution including:

- COMAddinRibbonExample

- LateBindingApi.Core

- OfficeApi

- Outlook Api

to get it all in one solution.

I also added a new class library "Extensibility" including the interface and enum files from IDTExtensibility2.cs.

Further more.. i did exclude the RibbonInterface.cs from the Project and used the NetOffice.OfficeApi.<interfaceName> instead (duplicated code?)

In VS2010 the libraries build platform target can be set to "any cpu". (not the executing lib due to registration problems)

Great work - thanks for your help!


Jul 28, 2011 at 10:19 PM

Hello Wolfang,

Sometimes i have problems in some of my projects if the RibbonInterfaces are defined in other Namespace as the addin.
I dont know why but these workarround helps.. thats the reason for duplicated code.
yes its as i said in the compatibility guide. NetOffice is also platform independent :)