Unable to create Cloud Sync tasks "Unknown command "lsjson""

[Jenlain74]

I created my cloud credentials with success (I tested with Google Drive, Mega and Hubic) BUT if I try to "verify credentials", I'm receiving an error :

Unknown command "lsjson"

When creating the Cloud Sync task, same error :

Error: Traceback (most recent call last):
File "/usr/local/lib/python3.7/site-packages/middlewared/main.py", line 130, in call_method
io_thread=False)
File "/usr/local/lib/python3.7/site-packages/middlewared/main.py", line 1084, in _call
return await methodobj(*args)
File "/usr/local/lib/python3.7/site-packages/middlewared/schema.py", line 961, in nf
return await f(*args, **kwargs)
File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/cloud_sync.py", line 966, in list_directory
return await self.ls(dict(cloud_sync, credentials=credentials), path)
File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/cloud_sync.py", line 976, in ls
raise CallError(proc.stderr, extra={"excerpt": lsjson_error_excerpt(proc.stderr)})
middlewared.service_exception.CallError: [EFAULT] 2020/07/20 12:01:34 Unknown command "lsjson"

I'm running a Freenas 11.3. This server has been installed long time ago (version 9 maybe) and regulary updated.

Could you please help me on this ?