Question

I’m trying to create a COM User Defined Function automation add in for Excel 2003/2007/2010 and create a setup program that will install the add-in without the error message “Cannot find add-in ‘mscoree.dll’. Delete from list?” occurring when the automation add-ins added to excel. This error occurs when running the setup program on PCs other than the development PC.

Using this example by Eric Carter combined with this Stack overflow answer. I have tried both methods of registering both the custom dll and mscoree.dll. Solutions for this problem are well described in both of those links however neither the registry edit of the setup program described in the stackoverflow link nor the code from the other link that should register mscoree.dll works for me when installing with a setup project on another PC (64 bit Windows 7 PC not used for building the program). (In fact the last comment on the Stack overflow link is a person with the exact same problem that I am describing here.) The add-in does work, I just want to prevent the error message.

Answer 1

I had this issue before and I noticed, through some experiments, that we must specify full path for the default value of InprocServer32 key in order to avoid seeing missing dll error message.

For 32-bit OS:
the value is C:\Windows\System32\mscoree.dll

For 64-bit OS:
the value is C:\Windows\SysWOW64\mscoree.dll

In C#, you can use the following code , Environment.GetFolderPath(Environment.SpecialFolder.SystemX86)
or Environment.SystemDirectory to get the path to the system folder.

The key, Programmable, is also used for listing your add-in in the automation server. Without it, you will not be able to find your add-in there.