The device is V5 platform and ISIS is enabled on the device. It is required to disable one interface. Use [Router-Ethernet 0/0/1]undo isis on the interface and the route learnt by ISIS is lost. Check configuration and related configuration of ISIS is lost.
undo isis command on the interface is error one. undo isis on the interface must follow the parameter. Correct one is undo isis enable. And then the interface does not enable ISIS.
Although the interface does not support undo isis, it can be executed. Under system view delete related data of ISIS and ISIS route of the device is lost.