RTD #N/A error in Excel 365 only when RTD COM object is registered at the user level

Question

I am developing a COM object that implements the excel RTD interface using .NET c#. It is a x64 bit project and office is also 64bit.

The 64bit RTD COM object works just fine in Office 2016 (also 64bit).

I can register the COM object at the CURRENT user level and Office 2016 loads it just fine. Machine level registry works just fine too.

However, when using office 365 64bit version. I can only get it to work when registered at the HKLM level.

I would like to get it to work at the User level. Not everyone in the organization using it may have admin rights to their machine.

Is there some way to get it to work? Am I missing more registry settings or is there some policy that is blocking it at the user level? NOTE: excel does recognize my COM object, but disables it. I cannot enable it at all. This all feels like some policy restriction new to office 365.

Answer 1

It looks like you didn't find the right hive in the windows registry for registering your RTD COM server on a machine with Office 365. See Add-ins for Office programs may be registered under the \Wow6432Node for possible routes.

I'd suggest investing your time for exploring capabilities of Add-in Express which allows creating installers for you. Also you may take a look at ExcelDNA.