Hi there, 

We have used the upgrade assistant to upgrade our solution from CMS11 to CMS12 and fixed any build issues associated with it; however when we run the solution it hangs. At the suggestion of one of the other forum posts, I have turned on debug logs and it is stopping at this point

The final action is:

"dbug: EPiServer.DataAbstraction.Internal.DefaultCategoryRepository[0]
      Populating Cache with Category tree."

Can anyone suggest a place to look to resolve this?