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

Hi

I have build a couple of test farms with almost the same SPAutoInstaller script and in both cases the managed Metadata service app worked perfectly .. In one of the servers, I have suddenly started getting. this error which I have never seen in any SharePoint 2013 farm I have built ...

Now this is a bit strange

• Both Manage Metadata service app and the corresponding web service are started.
• The permissions for the app pool account are correct as in all 3 check boxes checked
• the anonymous authentication in IIS is set to IUSR
• No 'obvious errors' in ULS except: The SharePoint Health Analyzer detected an error.  Drives are running out of free space.  Available drive space is less than twice the value of physical memory. This is dangerous because it does not provide enough room for a full memory dump with continued operation. It also could cause problems with 

Failed to get term store for proxy 'Managed Metadata Service'. Exception: System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.    
 at Microsoft.SharePoint.Taxonomy.Internal.XmlDataReader.GetDateTime(String name)    
 at Microsoft.SharePoint.Taxonomy.Internal.SharedTermStore.Initialize(IDataReader dataReader, Guid termStoreIdValue, Boolean fromPersistedData)    
 at Microsoft.SharePoint.Taxonomy.Internal.SharedTermStore..ctor(IDataReader dataReader, Guid termStoreId, Boolean fromPersistedData)    
 at Microsoft.SharePoint.Taxonomy.Internal.DataAccessManager.GetTermStoreData(MetadataWebServiceApplicationProxy sharedServiceProxy, Boolean& partitionCreated)

I was convinced that this server was on the August CU but damn it it's the Oct CU 

Any ideas as this really annoying. tho amusing to my client.

Daniel