Error when deleting target in use

I get the following traceback when deleting a target in use:

Error: Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/middlewared/main.py", line 137, in call_method
    result = await self.middleware._call(message['method'], serviceobj, methodobj, params, app=self,
  File "/usr/local/lib/python3.8/site-packages/middlewared/main.py", line 1191, in _call
    return await methodobj(*prepared_call.args)
  File "/usr/local/lib/python3.8/site-packages/middlewared/service.py", line 471, in delete
    rv = await self.middleware._call(
  File "/usr/local/lib/python3.8/site-packages/middlewared/main.py", line 1191, in _call
    return await methodobj(*prepared_call.args)
  File "/usr/local/lib/python3.8/site-packages/middlewared/schema.py", line 972, in nf
    args, kwargs = clean_and_validate_args(args, kwargs)
  File "/usr/local/lib/python3.8/site-packages/middlewared/schema.py", line 928, in clean_and_validate_args
    attr = nf.accepts[i]
IndexError: list index out of range