You receive the warning “Some of the properties associated with the solution could not be read” when opening a solution .SLN file in Visual Studio

Just today, I received the following error (or rather, a warning) message in Visual Studio 2013 after I had completed several branch merge operations in Team Foundation Server version control (TFS):

Some of the properties associated with the
solution could not be read.

At first, this seems like a strange error, and not much detail is given in the error message. Also, the error doesn't point you to the right direction, and the default Output window doesn't give any additional error.

However, I've myself seen this error happen several times, and thus also this time, I had the hunch that this error was somehow related to TFS version control settings in the .SLN file. Armed with this knowledge, I went into the Version Control part of the Output window, and there was a single line of prestigious information:

The following property is missing or has
incorrect value: SccLocalPath3

The easiest way to solve this issue is to open the .SLN in your favorite text editor, and the remove (or fix) the offending lines. If there are multiple lines causing errors, you can re-try to open the solution and see if the error message changes.

If nothing else helps, you might want to build the solution file completely from scratch. Of course, this is not very nice if you have a large solution with 50+ projects, but it's better to fix these kind of warnings before they bite you worse.

Hope this helps!