Hi,
Left click the wampmanager icon ( the W in the system tray ) -> PHP -> PHP Extensions
You should see another menu appear containing a long list of extension names.
Active ones have a tick beside them.
Click the one called php_mbstring and give wamp a few seconds to restart Apache, that will happen automatically.
You may need tor eload the PHP version for everything to work properly:
Wampmanager icon->PHP-Versions->5.5.12 then click on 5.5.12
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