Error in getting Interface Configs

[jpgoncalves123]

When i try to get interface config with the following path it raises an error:

path_intf = '{"Cisco-IOS-XR-ifmgr-cfg:interface-configurations": [null]}'
getconfig(path_intf)

The following paths for example work ok:
path_isis = '{"Cisco-IOS-XR-clns-isis-cfg:isis": [null]}'
path_route_Static = '{"Cisco-IOS-XR-ip-static-cfg:router-static": [null]}'
path_telemetry = '{"Cisco-IOS-XR-telemetry-model-driven-cfg:telemetry-model-driven": [null]}'

For path_intf the following error is raised:

[libprotobuf ERROR C:\projects\protobuf\protobuf\src\google\protobuf\wire_format_lite.cc:626] String field 'IOSXRExtensibleManagabilityService.ConfigGetReply.yangjson' contains invalid UTF-8 data when parsing a protocol buffer. Use the 'bytes' type if you intend to send raw bytes.
Traceback (most recent call last):
File "C:\Users\jpgoncalves\AppData\Local\Programs\Python\Python36\lib\site-packages\grpc\beta_client_adaptations.py", line 131, in _next
return next(self._iterator)
File "C:\Users\jpgoncalves\AppData\Local\Programs\Python\Python36\lib\site-packages\grpc_channel.py", line 364, in next
return self._next()
File "C:\Users\jpgoncalves\AppData\Local\Programs\Python\Python36\lib\site-packages\grpc_channel.py", line 358, in _next
raise self
grpc._channel._Rendezvous: <_Rendezvous of RPC that terminated with:
status = StatusCode.INTERNAL
details = "Exception deserializing response!"
debug_error_string = "None"