Managed Metadata Service or Connection is currently not available

Question

If I go to Term store Management "Site Settings Term Store Management Tool" I get the following error.

The Managed Metadata Service or Connection is currently not available. The Application Pool or Managed Metadata Web Service may not have been started. Please Contact your Administrator.

In addition my event viewer has errors like the following. In the end I am trying to edit wiki categories on a wiki publishing site which relies on management meta data.

Any ideas???

WebHost failed to process a request. Sender Information: System.ServiceModel.ServiceHostingEnvironment+HostingManager/33711845 Exception: System.ServiceModel.ServiceActivationException: The service '/SecurityTokenServiceApplication/securitytoken.svc' cannot be activated due to an exception during compilation. The exception message is: Exception has been thrown by the target of an invocation.. ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.InvalidOperationException: The farm is unavailable.

Answer 1

Check to see whether the Managed Metadata Service is actually running. Also see whether you can access it from central admin (could be a security issue where your webapp isn't authorised to talk to the Managed Metadata Service).

Answer 2

Make sure your app pool "SecurityTokenServiceApplicationPool" is Started. Also check other application pools where identity is set to network service.

I just stop this app pool and got same error.