After upgrade from 2007 to 2010 - Field Duplicate when trying to add feature

Question

I upgraded a sharepoint from 2007 to 2010 with attaching the content database. After that i developed a new solution with the same content type i used in 2007.

Adding the solution works fine but when trying to activate it i get

 The field with Id {GUID} defined in feature {GUID} was found in the current site collection or in a subsite.. 

What do I have to do to activate this solution and using the same field id like in 2007?

Answer 1

Did you try to deactivate the old feature?

If that doesn't work in place you can deactivate and remove it in the 2007 CDB and then do another upgrade. If you have content that was added after the initial upgrade you would have to merge that back in. You may lost data stored in the field when you deactivate it, so keep that in mind as well.