CustomTaskPane doesn't show up for win 7, does on dev machine

Question

I've built an EXCEL 2013 Add In. This is running on my development machine successfully. I am able to install this add-in using the Click-Once deployment on this same machine. In general this add-in runs perfectly on my machine, no matter if I am launching from visual studio, or I clean the project, uninstall from control panel, install from click-once deployment.

The symptom of not running is that the add-in's ribbon-tab actually shows up just fine. I have a button on this ribbon-tab that will make the CustomTaskPane visible, only when I install this on a user's machine that has windows 7 on it, the ribbon-tab still shows up but the button does nothing.

I modified the add-in so that it would automatically show the CustomTaskPane upon startup. It does not show up for the windows-7 user.

I've looked through the application log on the machine and don't find any related issues. Any suggestions on how to debug this further?

Answer 1

Steps to debug:

• Disable all the other Add-Ins.
• Add a Button on the Ribbon that will show the TaskPane on-demand.
• Add something on the Ribbon that will check on the TaskPane. Like Visibility property or anything else, really. This will confirm that your code can communicate with the TaskPane.
• Try make the TaskPane float, if it's docked, or vice-verse.

Answer 2

I guess that there should be this error

"Unable to cast COM object of type 'Microsoft.Office.Interop.Word.Something' to class type 'Microsoft.Office.Tools.Word.Something'. Instances of types that represent COM components cannot be cast to types that do not represent COM components; however they can be cast to interfaces as long as the underlying COM component supports QueryInterface calls for the IID of the interface."

Use try catch block and post the error in your question so that I can edit my answer.