UCS manager firmware upgrade is not working. All UCS B200M3 servers are running version 4.1.3nb, but the chassis I/O module and fabric interconnect are not upgrading.
Which infrastructure bundle are you trying to upgrade to? UCS 4.2 drops support for M3. That means you cannot have any M3 in the domain (not just decommissioned, but physically removed). We made the mistake of thinking we can run M3 on 4.1, with the infra bundle on 4.2. During the upgrade, it will upgrade the manager, determine that there is unsupported hardware and rollback Manager to the previous version.
Which FI model are you running? 4.3 drops support for FI-6200.