Can't upgrade any items on any character

[Tyrskorn]

Hi Yoshul,

This was a general issue around the time of your post, though since resolved.

More info here:

Upgrading items not working? (silvermoon)

Thank you for your reports. We’re working on a fix for the upgrade issue that will require realm restarts. We expect restarts to happen tonight for EU realms and tomorrow morning for US realms.