I can't seem to open my WhatsApp. When I click on it, it says "this version of WhatsApp has expired and that I should update. I updated it, and when I clicked on it again it's still saying the same thing.
Try deleting the app, restart your phone after you've uninstalled WhatsApp and try installing it again from the Windows Store. If that doesn't work, try installing it while the MicroSD card is removed.
Please note, that if you are running an older version of Windows Mobile, you might not be able to upgrade your version of WhatsApp.