1. Check the connection status of the MCU. It is found that the connection is normal.
2. Check whether a conference is in progress. There is no conference.
3. Check system configuration > conference configuration > Access number parameter > Access MCU configuration on the SMC2.0. It is found that the MCU is referenced in the access MCU configuration.
The MCU is referenced in the access MCU configuration and therefore cannot be deleted.
Select None and save the settings. The deletion is successful.