When I try to create a Excel 2007 Workbook project, in Visual Studio 2008, I get the following errormessage:
Project cannot be created because the ‘Excel Visual Studio Design-Time Adaptor Add-in’ is not working correctly. Excel might have disabled the add-in or made it inactive, or all add-ins might be disabled in your Trust Center settings. Check the add-in status in Excel Options. If the add-in is active and enabled, reinstall or repair Visual Studio Tools for Office.
I have verified that the add-in is not inactive or disabled and I have tried to repair and uninstall/reinstall VSTO several times.
What to do?
Just in case you haven’t checked the trust settings, this MSDN page describes how to.
I came across this on a MSDN forum:
Failing that, I think you will have to run a repair on the Visual Studio 2008 installation (put the installation DVD in a drive, and select the repair option).