Visual Studio 2013 - Cannot merge Views

Question

For a couple of weeks now I have been unable to merge Views within Visual Studio 2013 in response to conflicts when getting Source Code from Visual Studio Team Services. I am sure I used to be able to this (we recently moved from Visual Studio Professional 2012 so I cannot be one hundred percent certain - automerging may have been sufficient in the early days of the project).

The "Accept Merge" and move to next change/conflict buttons are all greyed out and inoperable. See screenshot snippet-

This originally only happened with Views, but now seems to affect some other classes. Changes are highlighted and indicated on the scroll bar so the diff tool otherwise appears to be functioning. This only originally affected me, but now affects a new colleague into the team.

I can still either Keep Local Version or Take Server Version but this is rarely sufficient. This leaves me manually altering the local copy to apply changes highlighted by the merge tool. (Edit - See a better workaround in "Second Update" below).

Has anyone come across this before?

Visual Studio 2013 Premium (patch RTM/Update 1/Update 2 - all with the same problem), with Resharper 8.2 (originally 8.0.2) C# and Web Essentials installed. Running on Windows 7 Professional x64.

Project is ASP.NET 4.5 using MVC 5.1.2 (now additionally updated from MVC 5 where the problem first occurred) (upgraded from MVC 4 following the upgrade instructions on the ASP.NET website) in C#, using latest versions of Razor (3.1.2) and Entity Framework (6.1.0 RTM).

Edit: Initially a repair install of Visual Studio 2013 appeared to have fixed the issue. It has now however returned exactly as it was before. Since it took an hour to do the repair I cannot repeatedly do this in order to merge views. I am currently able to round trip the solution between Visual Studio 2012 Update 4 and Visual Studio 2013 in order to do merges in Visual Studio 2012 where it is working normally.

Second Edit: I am currently manually resolving conflicts by selecting the desired code (local/server), saving the merge window and then closing it which will prompt to accept the merge result. This seems to function but is obviously sub-optimal. It may however be helpful for other users.

Answer 1

In the event, installing Resharper 8.1 on top of 8.02 appears to have fixed it fixed it briefly before the problem returned yet again. I had previously completed a repair install of Visual Studio Premium 2013 as well - which briefly seemed to have fixed it before it broke again. I only mention it in case the fix is cumulative.

I am unclear if it was a bug in Resharper that was somehow preventing the merge, or a persistent problem with the installation that the upgrade cleaned up (Resharper removes previous versions and then installs updates, rather than attempting to install over the top). Update - I am extremely confident that this is not related to ReSharper and that it was the configuration of Visual Studio as a result of re-installing the extension and not the extension itself that fixed the issue.

In either case, the issue (for now) seems to have disappeared and this seems to be related to the upgrade, or is an extremely strong co-incidence.

Colleagues with the same versions of Visual Studio and Resharper, working on the same project, the same version of Windows and (in one case) the same hardware were not affected, so it seems likely it is an edge case niche issue caused by corrupted data somewhere.

I have a current working theory that this is related to different patch versions of Visual Studio (for example Visual Studio 2012 Update 2, Visual Studio 2013 RTM, Visual Studio 2013 Update 1, Visual Studio 2013 Update 2. This only affects Visual Studio 2013 for us.

Answer 2

Simple solution I use is carry on with your manual merge process once you are done simply Close the Merge-* tab (the one you are using to merge files) this will bring up a prompt for confirming if you want to Save the changes made (this is the merge changes you made to your local file) click 'yes' Now it comes back to Resolve Conflicts tab and brings up another prompt asking if you want to Accept Merge Result, click 'yes'(this is same as the button Accept Merge)