IRibbonExtensibility GetCustomUI not called
问题 I'm developing a shared add-in for Outlook. One of my customers is experiencing trouble on his machine, he does not see my add-in buttons/ui in the main window ribbon. After exploring his environment and my logs I noticed that the function "GetCustomUI" of interface IRibbonExtensibility is not being called in his environment. I'm not sure what can be the cause for the different behavior, why doesn't Outlook call the GetCustomUI on the customer machine? Also - Is it possible to initiate a call