Why I cant reconcile file differences in TFS 2010?

Question

We are using TFS 2010.

In 2 branches I have file that is clearly different in each branch. When I compare branches this file is displayed as different, but reconcile option is grayed out. If I try to merge, I get message that there is nothing to merge. Can somebody please shed some light here? Thanks.

For those willing to read more, here is the scenario I am facing often and I don't know how to deal with it:

There are 4 branches:
- Main branch
- Release branch (child of main branch)
- Developer1 branch (child of release branch)
- Developer2 branch (child of release branch)

Developer1 and Developer2 made changes in their branches and merged code to Release branch. In meantime, changes were done in Main branch (Urgent Fix or whatever). When changes are deployed, I made attempt to merge code to Release branch. Merging proved to be difficult as there were too many code conflicts at this point. So I made decision to take source branch (main) when resolving differences (that removed all changes made by Developer1 and Developer2 from Release branch). Now, I would like to ask Developer1 and Developer2 to merge their changes again and resolve their own conflicts. But, they can't merge, nor reconcile.

Answer 1

After you compare a server folder and a local folder, you can reconcile the differences between the folder contents and between files that have conflicting pending changes in your local folder.

You should also meet below required permissions

To perform these procedures, you must have the Read and Check out permissions set to Allow. For more information, see Permissions and groups reference.

More details take a look at this official tutorial--Reconcile differences between two folders

A step by step process show hot to use reconcile command, you could take a look at this reply here: How to have TFS 2010 detect changes done to files outside of Visual Studio?