FPR 1120 CLI show managers

[edp-adm]

I have 2x FPR1120 in HA managed by FMC, i've executed "show managers" on both and one of them shows some kind of error, both of them running software

Cisco Firepower Extensible Operating System (FX-OS) v2.13.0 (build 1022)
Cisco Firepower 1120 Threat Defense v7.3.1.1 (build 83)

show managers
Type : Manager
Host : ....
Display name : ....
Version : 7.4.0 (Build 118)
Identifier : ...
Registration : Completed
Management type : Configuration and analytics

Type : Error: Unidentified role 0

what's that error and how to get rid of it?

[Marvin Rhoads]

You are using FMC 7.4 which is not compatible with Firepower 1120 running 7.3.1.1. Version 7.4 is ONLY for Firepower 4200 series. When 7.4.1 is released later this year it will support all other non-End-of-Sales appliances.