Project Web App Cannot connect to Project Server

PROBLEM

System.ServiceModel.FaultException`1[[Microsoft.Office.Project.Server.Interfaces.DefaultServerFault, Microsoft.Office.Project.Server.Communications, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c]]: The databases are out of the range of compatibility, upgrade your databases.   Server stack trace:    

 at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)   

 at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)   

 at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)   

 at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)    Exception rethrown

 at [0]:    

 at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)   

 at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)   

 at Microsoft.Office.Project.Server.Interfaces.IAuthentication.GetUserByName(String username)   

 at Microsoft.Office.Project.Server.AuthenticationHelper.AuthenticateUserByName(String userName, Guid siteId)   

 at Microsoft.Office.Project.PWA.PJContext.AuthenticateUserForPWA(Boolean needToValidateUser, String username, Guid siteId)

PROBLEM

If you get the above, you can try the following:

1. Start and restart the Project Services

2. Run the SP Configuration Wizard on the Project Server