Project item ‘4294967294’ does not represent a file, this error comes out when I try to open a solution which results in some of the projects can not be loaded (the source file is on the right location and path). I’ve spent two hours to three hours to resolve this issue.
This problem can be resolved by checking out all the files under that solution (from tfs explorer, before you open the solution on your visual studio) and it will resolve the problem for sure. but it’s not practical if you keep doing this and it’s not good to check out all the files if you are not using it.

The root of this problem is caused by Reporting Project. in detail,I’ve checked in reportname.rdl.data for every single report and reportsprojectname.rptproj.user file. Those files must not be checked in at all, remove it from your TFS or VSS and it will work.