I tried again and ERA explorer gave same error that MS Office 365 version is not compatible. I am suspecting that updated version of Explorer is not being downloaded automatically.
Launcher log has below messages:
2018/01/23 13:57:51 failed to get update dir. reason: open config\config.json: The system cannot find the path specified.
2018/01/23 14:04:28 failed to get update dir. reason: open config\config.json: The system cannot find the path specified.