<An error occurred while retrieving package metadata for \'bootstrap.3.3.5\' from source \'nuget.org\'. ========== Finished ==========
Open the solution in Visual studio -> Navigate to packages.config file 1/ copy the package attribute of corrupted package that you see in the error console. Remove that corrupted package attribute from package element 2/ save packages.config file and then run nuget command 3/ when successfull, place back the package attribute