Create a pool error

[ghost]

it returns this AttributeError when I ran this to create the pool :

---

az batch pool create --template pool-ffmpeg.json --account-name ****** --account-endpoint ******.westeurope.batch.azure.com
This package of the Batch Extensions module supports Azure Batch up to version 4.1. The current version 4.1.1 has not been tested for compatibility.
The behavior of this command has been altered by the following extension: azure-batch-cli-extensions
You are using an experimental feature {Pool Template}.
poolId (The pool id ): ffmpeg
nodeCount (The number of pool nodes): 2
You are using an experimental feature {Package Management}.
'function' object has no attribute 'metadata'
Traceback (most recent call last):
File "/opt/az/lib/python3.6/site-packages/knack/cli.py", line 197, in invoke
cmd_result = self.invocation.execute(args)
File "/opt/az/lib/python3.6/site-packages/azure/cli/core/commands/init.py", line 344, in execute
cmd.exception_handler(ex)
File "/opt/az/lib/python3.6/site-packages/azure/cli/command_modules/batch/_exception_handler.py", line 30, in batch_exception_handler
reraise(*sys.exc_info())
File "/opt/az/lib/python3.6/site-packages/six.py", line 693, in reraise
raise value
File "/opt/az/lib/python3.6/site-packages/azure/cli/core/commands/init.py", line 319, in execute
result = cmd(params)
File "/opt/az/lib/python3.6/site-packages/azure/cli/core/commands/init.py", line 180, in call
return super(AzCliCommand, self).call(*args, **kwargs)
File "/opt/az/lib/python3.6/site-packages/knack/commands.py", line 109, in call
return self.handler(*args, **kwargs)
File "/opt/az/lib/python3.6/site-packages/azure/cli/core/init.py", line 420, in default_command_handler
result = op(**command_args)
File "/home/sa/.azure/cliextensions/azure-batch-cli-extensions/azext_batch/custom.py", line 110, in create_pool
client.pool.add(pool, add_option)
File "/opt/az/lib/python3.6/site-packages/azure/batch_extensions/operations/pool_operations.py", line 124, in add
return super(ExtendedPoolOperations, self).add(pool, pool_add_options, custom_headers, raw, **operation_config)
File "/opt/az/lib/python3.6/site-packages/azure/batch/operations/pool_operations.py", line 277, in add
url = self.add.metadata['url']
AttributeError: 'function' object has no attribute 'metadata'