A new update is available for Base SAS , version 9.4_M4 :
Remote Library Services library allocation fails with \"ERROR: Invalid libref...\"
\"ERROR: An exception has been encountered\" occurs when registering a table in a concatenated library that contains a SAS® metadata-bound library
Note: A comprehensive list of all SAS hot fixes is available from support.sas.com. You can use the SAS Hot Fix Analysis, Download, and Deployment (SASHFADD) tool to manage your SAS hot fixes.