"Could not find the source control provider associated with this solution" appears in the project. Project will be treated as not under source control "

Workaround:
1.VS2013 Open the project,

2. Tip "The solution you are opening is already bound to source control on the following team Foundation server: Http://IP: Port/tfs/defaultcollection. Do you want to contact this server to try to enable source control integration?

3. Select "No n"

4. Tip "The solution appears to be under source control, but cannot find his binding information." Because these missing information cannot be automatically recovered, items that are missing bindings will be treated as not under source code control. "Select" OK "

5. In the Solution Explorer on the right, right-click on each item >> edit **.csproj
6. Removal

<SccProjectName>SAK</SccProjectName>
<SccLocalPath>SAK</SccLocalPath>
<SccAuxPath>SAK</SccAuxPath>
<SccProvider>SAK</SccProvider>

7. In the Solution Explorer on the right, right-click on each item >> reload

=================================================================================================
Method Two:
1. Modify the solution file **sln
1.1 Remove the read-only attribute of the file
1.2 delete the following characters in the solution file **sln
---------------------------------------------- --
Globalsection (Teamfoundationversioncontrol) = presolution
Sccnumberofprojects = 6
Sccenterpriseprovider = {4ca58ab2-18fa-4f8d-95d4-32ddf27d184c}
Sccteamfoundationserver = Http://IP: Port/tfs/ Defaultcollection
SccLocalPath0 =.
SccProjectUniqueName1 = ****.csproj
SccProjectName1 = * *
SccLocalPath1 = * *
SccProjectUniqueName2 = * *. csproj
SccProjectName2 = * *
SccLocalPath2 = *
SccProjectUniqueName3 = **.csproj
SccProjectName3 = * *
SCCLOCALPATH3 = * *
SccProjectUniqueName4 = **.csproj
SccProjectName4 = * *
SccLocalPath4 = *
SccProjectUniqueName5 = **.csproj
SccProjectName5 = * *
SccLocalPath5 = *
Endglobalsection
------------- -----------------------------------

Settings.Designer.cs will be changed automatically
Reference.cs will be changed automatically

You can also remove the read-only attribute from the entire project folder, and you will not be prompted to modify it later

"Could not find the source control provider associated with this solution" appears in the project. Project will be treated as not under source control "