xlfRegister call failed for function or command

[Niels Bosma]

I have a user reporting that he's getting this error:

 Registration [Error] xlfRegister call failed for function or command: 'W3CValidate'

in the ExcelDna log-window. What could be wrong?

http://community.seotoolsforexcel.com/t/seo-tools-error-when-opening-new-sheets/30

[Govert van Drimmelen]

Hi Niels,

It's a similar error to this one: https://groups.google.com/forum/#!topic/exceldna/-YO3Ish-BRg

xlfRegister would fail if called from inside a UDF.

The registration might be the moment where the method is JIT-compiled, so any dependencies that are not available or fail to load might cause problems here.

Is something special about that function, or the moment where it is being registered?

Otherwise, you need to figure out why this machine or context is special.

Does the rest of your add-in work?

Does a simple add-in work on that machine?

-Govert