is not a valid storage account name. The storage account name must contain at least 3 characters and use lower-case letters ...

'{0}' is not a valid storage account name. The storage account name must contain at least 3 characters and use lower-case letters and numbers only.
To create a Storage Account, login to the Windows Azure Portal (http://windows.azure.com), select your project, click on New Service, and then click on Storage Account.