Seems that you do not have any management VMkernel port or it might have been removed. you may have to verify the same.
run esxcli network ip interface list to check if there are any VMKernels.
it wont generate re any output if NO vmkernel ports are available.
if No VMkernel ports then follow the below to re-create the VMkernel Management port group.
esxcli network ip interface add -i=vmk0 -p="Management Network -M="MAC Address"" to create a VMKernel for management. Make sure the right MAC Address of the Uplink is mentioned.
And make sure that it is a unique vmk, does not match an existing vmk like ( vmk0, vmk1, vmk2).
Once the Port is created you should be able to the Configure Management Network on the DCUI
Hope this is helpful.