This article describes about the probable cause and fix for FortiSwitch 'Module in ERROR state' error.

For version 6.4.4.

- FortiSwitch SFP/SFP+ port may not come up.
- FortiSwitch may report high CPU usage.

1) '# get switch modules status' and ' # get switch modules summary' command outputs may show 'Module in ERROR state' as shown below from CLI:
# get switch modules status
Module in ERROR state

# get switch modules summary

  Portname State Type Transceiver RX Vendor Part Number Serial Number
  __________ _______ _______ ____________ ___ ________________ ________________ ______________

  port5 ERROR
  port6 ERROR
2) This error may also increase FortiSwitch CPU usage due to ‘Diagnostic Monitoring Interface (DMI)’ 'dmid' process:
# get system performance status
CPU states: 1% user 66% system 0% nice 43% idle
Memory states: 11% used
Average network usage: 0 kbps in 1 minute, 0 kbps in 10 minutes, 0 kbps in 30 minutes
Uptime: 15 days, 10 hours, 29 minutes

# get system performance top
Run Time: 15 days, 10 hours and 29 minutes
0U, 57S, 43I; 2023T, 1712F
            dmid 1858 R 97.0 0.5 ---------------- > dmid
   igmpsnoopingd 1822 R N 1.9 0.7
           ctrld 1851 S 1.9 0.5
            lfgd 1820 S 1.9 0.5
        lldpmedd 1857 S 0.9 0.7
3) To overcome FortiSwitch 'Module in ERROR state' error – use supported FortiSwitch Transceiver suitable for the FortiSwitch Model, refer below link for FortiSwitch Compatible Transceivers list:

Note: For updated FortiSwitch Compatible Transceivers list visit: https://docs.fortinet.com

4) If feasible, upgrade FortiSwitch firmware to latest firmware when there’s a maintenance window and console cable access to the FortiSwitch

5) If the above step does not resolve the issue, contact Fortinet Support and attach below data for analysis:

- FortiSwitch Model
- Transceiver Make and Model:
- Validate if Transceiver model is supported on FortiSwitch Model (refer FortiSwitch Compatible Transceivers list).
- Attach following logs from FortiSwitch:
# show full-configuration switch interface
# show full-configuration system interface
# show full
# diag debug report

# diagnose switch modules state-machine
# get switch modules detail                    
# get switch modules summary                   
# get switch modules status               
Related link.

FortiSwitch™-Compatible Transceivers