Error backing up Exchange 2016

Fighting with the backup for my Exchange 2016 server. It was working fine. Then upgrading to 6.4 caused issues and I had to reinstall the Agents. now the Exchange server will not back up. Gives the error below. Any suggestions?

The transfer failed: 'Call to service method exch:8006/.../snapshots POST failed: The transfer failed: 'Insufficient memory to continue the execution of the program.''