Unable to deploy via appcfg or gcloud

[Jeremy D]

We can't seem to deploy our application, out of the blue, as of yesterday afternoon. appcfg only returns a 400 bad request error, no other information given. Below is a copy of what gcloud returns, seems to offer a bit more detail but nothing we can seem to solve on our end. 

Nothing about our environment or any fundemental code has been changed. There seems to be no rhyme or reason as to why we suddenly can't deploy. This is to any version. We also have a separate app ID for testing, we can't deploy to that either.

Updating service [default]...\DEBUG: Received operation: [apps/<app id>/operations/15647c11-0a49-46cc-a52d-0bb85e4b96e0]
DEBUG: Operation [apps/<app id>/operations/15647c11-0a49-46cc-a52d-0bb85e4b96e0] not complete. Waiting 5s.
Updating service [default]...|DEBUG: Operation [apps/<app id>/operations/15647c11-0a49-46cc-a52d-0bb85e4b96e0] not complete. Waiting 5s.
Updating service [default].../DEBUG: Operation [apps/<app id>/operations/15647c11-0a49-46cc-a52d-0bb85e4b96e0] complete. Result: {
    "metadata": {
        "user": "<my email>",
        "target": "apps/<app id>/services/default/versions/dev-jeremy",
        "@type": "type.googleapis.com/google.appengine.v1beta5.OperationMetadataV1Beta5",
        "insertTime": "2018-01-17T18:02:35.848Z",
        "method": "google.appengine.v1beta5.Versions.CreateVersion"
    },
    "done": true,
    "name": "apps/<app id>/operations/15647c11-0a49-46cc-a52d-0bb85e4b96e0",
    "error": {
        "message": "An internal error occurred.",
        "code": 13
    }
}
Updating service [default]...failed.
DEBUG: (gcloud.app.deploy) Error Response: [13] An internal error occurred.
Traceback (most recent call last):
  File "/Users/jeremy/google-cloud-sdk/lib/googlecloudsdk/calliope/cli.py", line 720, in Execute
    resources = args.calliope_command.Run(cli=self, args=args)
  File "/Users/jeremy/google-cloud-sdk/lib/googlecloudsdk/calliope/backend.py", line 1455, in Run
    resources = command_instance.Run(args)
  File "/Users/jeremy/google-cloud-sdk/lib/surface/app/deploy.py", line 53, in Run
    return deploy_util.RunDeploy(self, args)
  File "/Users/jeremy/google-cloud-sdk/lib/googlecloudsdk/command_lib/app/deploy_util.py", line 300, in RunDeploy
    all_services)
  File "/Users/jeremy/google-cloud-sdk/lib/googlecloudsdk/command_lib/app/deploy_util.py", line 167, in Deploy
    service, manifest, image, endpoints_info)
  File "/Users/jeremy/google-cloud-sdk/lib/googlecloudsdk/api_lib/app/appengine_api_client.py", line 118, in DeployService
    return operations.WaitForOperation(self.client.apps_operations, operation)
  File "/Users/jeremy/google-cloud-sdk/lib/googlecloudsdk/api_lib/app/api/operations.py", line 70, in WaitForOperation
    encoding.MessageToPyValue(completed_operation.error)))
OperationError: Error Response: [13] An internal error occurred.
ERROR: (gcloud.app.deploy) Error Response: [13] An internal error occurred.

[Jeremy D]

May have found the culprit. Possible that one of us working in dreamweaver or similar, that application stored a "Icon" system/hidden file and somehow that got checked into our version control. 

[George (Cloud Platform Support)]

What messages do you receive when deploying with the --verbosity debug parameter? 

It looks as if you are notified by means of the same "code=13" issue as covered in this Google Groups thread or this Public Issue Tracker case. One of the suggested workarounds were the deployment with the "appcfg.py" command. 

Have you established the root cause of this issue, in your case? Are the errors gone?