Diablo3: EU/ASIA Wrong Region Game Client Fix

If you are using the wrong region game client, you are going to have a bad time with patches. How to fix errors logging into Europe or Asia Servers after 1.0.2 Patch.

Patch 1.0.2 was released today and the Americas servers are currently down for maintenance/patching. Europe and Asia players who have downloaded the wrong client, English (US), will have had their clients patched before the EU servers, thus causing an inability to log-in to their EU characters despite the EU servers being up and running. You know you have this error if the pre-launcher states that "Game is ready" but when signing-in you are asked to update the game (the game crashes soon after).

The best way to fix this is to uninstall Diablo 3 and log into your account on Battle.net and change your 'Full Game Client' to English (EU) or another language associated with the region you are playing in and re-installing.

I have just done so myself and can confirm that I am logged into EU on client 1.0.1 having previously had issues logging in with 1.0.2 onto EU characters.