KEY ERROR while creating VLAN

[NinthWave]

I am trying to add a new VLAN and when I hit apply, I get an error message:

Code:

Error: Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/middlewared/main.py", line 138, in call_method
    result = await self.middleware._call(message['method'], serviceobj, methodobj, params, app=self,
  File "/usr/local/lib/python3.9/site-packages/middlewared/main.py", line 1213, in _call
    return await methodobj(*prepared_call.args)
  File "/usr/local/lib/python3.9/site-packages/middlewared/service.py", line 495, in update
    rv = await self.middleware._call(
  File "/usr/local/lib/python3.9/site-packages/middlewared/main.py", line 1213, in _call
    return await methodobj(*prepared_call.args)
  File "/usr/local/lib/python3.9/site-packages/middlewared/schema.py", line 975, in nf
    return await f(*args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/middlewared/plugins/network.py", line 1533, in do_update
    await self.middleware.call('interface.enable_capabilities', iface['name'], capabilities)
  File "/usr/local/lib/python3.9/site-packages/middlewared/main.py", line 1256, in call
    return await self._call(
  File "/usr/local/lib/python3.9/site-packages/middlewared/main.py", line 1224, in _call
    return await self.run_in_executor(prepared_call.executor, methodobj, *prepared_call.args)
  File "/usr/local/lib/python3.9/site-packages/middlewared/main.py", line 1128, in run_in_executor

I must say that bce1 is not connected to the switch yet...