While working with Term Store Management Tool, I received the following error in SharePoint 2013.
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.
One or more solution might apply in this case too.
Solution 1: Ensure Managed Metadata Service Application is Configured
Solution 2: Ensure Managed Metadata Service Application Permissions
Ensure Administrators & Permissions are properly configured.
Solution 3: Ensure Managed Metadata Service is Running
Open Central Administration > Manage Services page
Ensure the Managed Metadata Service is Started. If not, click the Start link to start it.
Once the problem is solved, we can see the Term Store Management Tool started working.