“I installed my Office solution (VSTO add-in) successfully but when I open the Office application, my add-in does not load. What is the problem?” This is a common question which I came across many times in Forums. Here are simple and quick checks that you can do before you start scratching your head or jump to the Forums. I’ll be using Excel as the Office application, but the approach is applicable to others more or less. Make sure your add-in is installed correctly and it is enabled Open registry editor and navigate to “ ”.

Here is how this registry key looks like after I installed MyExcelAddin: The registry string we are interested in the most is the LoadBehavior. Whenever you see '3' (Loaded at Startup) as the value of this string you are good in this part and your add-in tries to load when the Excel starts. For more information about registry entries for application-level Office solutions see. Check out “COM Add-Ins” dialog in Excel Now open Excel and see if your add-in loads successfully. If not, open Excel Options dialog (File->Options) and navigate to Add-Ins tab. “Healthy add-ins” show up as “Active Application Add-ins”, however, if an add-in is disabled for whatever reason, it will appear under the “Inactive Application Add-ins”.

You can select the “COM Add-ins” from the Manage dropdown at the bottom of this dialog and see the LoadBehavior of all COM add-ins. In normal cases, the add-in should be checked and its 'Load Behavior' should be “Loaded at Startup”: If the VSTO runtime encounters a problem loading the add-in, you’ll see this message instead. “Load Behavior: Not Loaded.

Dec 20, 2018 - The BlueJeans meeting credentials and instructions will appear. Fill in your. The Add-In gives you the choice of using your Personal Meeting ID or Scheduled Meeting ID. Outlook for Mac does not support standard add-ins.

A runtime error occurred during the loading of the COM Add-in”. Find the problem Set the 'VSTO_SUPPRESSDISPLAYALERTS' environment variable to 0.

Then go back to the registry key I mentioned in step 1 and set the LoadBehavior to 3. Now restart the Excel. You should be able to see a dialog describing what is happening: It is also a good practice to enclose the code inside the add-in's startup event in a try-catch block and log all exceptions. Hard disabled add-ins If an add-in causes the Office application to crash (close unexpectedly), the add-in gets “hard disabled”.

Please follow instruction to re-enable the add-in. In addition, you might want to check the “HKEY_CURRENT_USER Software Microsoft Office 12.0 Excel Resiliency DisabledItems” (replace 12.0 with 11.0 for Office 2003 and with 14.0 for Office 2010). Your add-in should not have an entry under this registry key. More References: •.

Hamed, I've done all steps as mentioned in your post, but I couldn't get my addin for Outlook 2010 enabled 🙁 I've set VSTO_SUPPRESSDISPLAYALERTS = 0 too, but No Error dialog popup. But add-in does not get enabled. Load Behaviour is set to 3, but as soon as outlook 2010 loads, it gets converted to 2. Can you help me here?. It is really getting irritating for me, since I could not produce an exception box so that i can know where error is occurring My Dev platform works fine. It happens only on client PC. The PC has Office 2010 32-bit, Windows 7 x64,.Net 4.0 Client Profile and VSTO 2010 runtime already installed.

Hi Varun, Let me clear some points first: 1. I am assuming your VSTO solution targets.NET 4.0 client. Are you using MSI or ClickOnce?

If MSI, have you verified that all required registry keys are created? Look here: 3. What Office 2010 and VS2010 you are using? Can you give me the build numbers? Font Have you wrapped the entire code in the addin startup within a try-catch block?

Any exception? When you say 'it works fine on the Dev platform', are you debugging on the dev machine or you really installed the addin? (please note that you need to do a 'clean solution' on the VSTO project in VS before installing the addin on your dev machine and uninstall the addin if you want to go back to debugging!).

Also what are differences between your dev machine and target one? Different OS, VS, Office? (even build numbers or the order you installed these). Do you have ANY other addin on the PC target that works? Do you have any other machine (preferably similar to the dev machine) that you can install the addin?

Yes, solution targets.Net 4.0 Client Profile 2. Using MSI Installer for deploy.

And all mentioned Registry entries exists. Version Info: VS 2010 Ultimate – 10.0.30319.1 RTMRel Outlook 2010 – 32-bit – 14.0.4760.1000 4. Yes, I've wrapped the code in try/catch but not working. Also, you should know that the project was originally in VS 2005 for outlook 2007, and have been upgraded to VS 2010 recently. On Dev machine it works fine in debugging way, I've not tried installing it on Dev machine.