mscorlib version conflict during build

Question

On a new Win8.1 reinstall, with all of my code restored from backup, I\'m suddenly now getting a Visual Studio warning when I build the main project of my solution:

Answer 1

I was able to fix this by issuing an update-package -reinstall command at the Package Manager Console.

BUT

Be careful, updating all the packages in your solution could cause other problems, make sure you can roll back to a good version if it goes wrong!

Answer 2

Following Memet Olsen's advice using VS2017 community...almost identical:

• Right click Solution in Solution Explorer.
• Select 'Manage Nuget Packages for Solution'
• Check the packages. If any of them have a blue up-arrow rather than a green tick use the 'update' button