We had come across with the very strange issue with one of our customer.
Where our Office Add-In loads and shows in ribbon but only the creation of Taskane with ActiveX control is not working with exception(Unable to create specified ActiveX control) when the UAC is disabled.
Taskpane with ActiveX control seems to be loading only when UAC settings changed to any level and without clicking OK(I mean without applying the UAC settings).
Creation of Taskpane with ActiveX control fails
when UAC settings changed and clicked OK(I mean UAC settings are applied) and the same behavior observed post restarting the machine again.
The error we see on the logs is "System.Runtime.InteropServices.COMException (0x80004005): Unable to create specified ActiveX control".
We couldn't able to replicate this issue from our side.
Customer trying our Add-In with newly imaged virtual machines and their OS is Windows 10(Version 1803(OS Build 17134 1667)),MS Office 2016 and .Net framework version : 4.8.03761
Is it related to any Microsoft patches for Office 2016 OR .NET Framework 4.8?
Customer wants to know on the particular update causing this issue.
We used to change UAC settings to top 3 levels as a workaround and that resolved similar issues for different customers but that is not helping this customer now.
Please help here on this issue
Thanks in advance.
