I have been running a variational circuit optimizing the parameters on the "melbourne" device. The system launches multiple jobs in parallel, and only gets the jobs accepted that my credit allows. The remainder get queued with the following message:

"FAILURE: Can not get job id, Resubmit the qobj to get job id.Error: 403 
Client Error: Forbidden for url: https://api.quantum-computing.ibm.com/api/Network/ibm-q/Groups/open/Projects/main/Jobs?
access_token=.... Your credits to run jobs are not enough, Error code: 3458." 

This is normal, and it continues till the program runs till completion.

Unfortunately, I have encountered a new error that actually halts the program and throws the error shown below (520 Server Error).

My questions:

  • Why is this happening?
  • What can I do against it?


FAILURE: Can not get job id, Resubmit the qobj to get job id.Error: 403 Client Error: Forbidden for url: https://api.quantum-computing.ibm.com/api/Network/ibm-q/Groups/open/Projects/main/Jobs?access_token=.... Your credits to run jobs are not enough, Error code: 3458.
Traceback (most recent call last):
  File "file.py", line 307, in <module>
  File "file.py", line 284, in QSVMsetup
training_result = svm.train(df_train_test_x_Q, df_train_test_y_Q, quantum_instance)
  File "vqc.py", line 437, in train
gradient_fn=grad_fn  # func for computing gradient
  File "/home/user/.local/lib/python3.6/site-packages/qiskit/aqua/algorithms/adaptive/vq_algorithm.py", line 118, in find_minimum
  File "/home/user/.local/lib/python3.6/site-packages/qiskit/aqua/components/optimizers/spsa.py", line 131, in optimize
max_trials=self._max_trials, **self._options)
  File "/home/user/.local/lib/python3.6/site-packages/qiskit/aqua/components/optimizers/spsa.py", line 182, in _optimization
cost_minus = obj_fun(theta_minus)
  File "/home/user/ibm/vqc_mod_v10.py", line 476, in _cost_function_wrapper
predicted_probs, predicted_labels = self._get_prediction(self._batches[batch_index], theta)
  File "/home/user/ibm/vqc_mod_v10.py", line 348, in _get_prediction
results = self._quantum_instance.execute(list(circuits.values()))
  File "/home/user/.local/lib/python3.6/site-packages/qiskit/aqua/quantum_instance.py", line 312, in execute
self._skip_qobj_validation, self._job_callback)
  File "/home/user/.local/lib/python3.6/site-packages/qiskit/aqua/utils/run_circuits.py", line 343, in run_qobj
logger.info("Backend status: {}".format(backend.status()))
  File "/home/user/.local/lib/python3.6/site-packages/qiskit/providers/ibmq/ibmqbackend.py", line 112, in status
api_status = self._api.backend_status(self.name())
  File "/home/user/.local/lib/python3.6/site-packages/qiskit/providers/ibmq/api_v2/clients/account.py", line 64, in backend_status
return self.client_api.backend(backend_name).status()
  File "/home/user/.local/lib/python3.6/site-packages/qiskit/providers/ibmq/api_v2/rest/backend.py", line 58, in status
response = self.session.get(url).json()
  File "/home/user/.local/lib/python3.6/site-packages/requests/sessions.py", line 546, in get
return self.request('GET', url, **kwargs)
  File "/home/user/.local/lib/python3.6/site-packages/qiskit/providers/ibmq/api_v2/session.py", line 166, in request
raise RequestsApiError(ex, message) from None
qiskit.providers.ibmq.api_v2.exceptions.RequestsApiError: 520 Server Error: Origin Error for url: https://api.quantum-computing.ibm.com/api/Network/ibm-q/Groups/open/Projects/main/devices/ibmq_16_melbourne/queue/status?access_token=...

1 Answer 1


This is likely because the Melbourne device is currently offline for upgrades, it should be back up in around 2 weeks. If you join the Slack workspace, linked from the qiskit website and then join the #ibm-q-systems channel you can get updates about all the devices and when they will be taken offline.

  • $\begingroup$ Thanks. Slack is blocked per corporate policy. Is there also a website with this information? $\endgroup$ Dec 5, 2019 at 15:03
  • $\begingroup$ It is available on the IBM Q Experience website, although curiously that is saying Melbourne is online.. Is this an issue you have encountered only recently? $\endgroup$
    – met927
    Dec 5, 2019 at 15:25

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