JSONDecodeError Invalid \escape: line 1 column 864 (char 863)

[nsumaila]

...
File "gatewaypagamento/utils/pagamento_mpesa.py", line 91, in receiveFunds
transResult = api_request.execute()
File "portalsdk/api.py", line 21, in execute
return {
File "portalsdk/api.py", line 54, in __post
return APIResponse(r.status_code, json.loads(r.headers.str().replace("'", '"')), json.loads(r.text))
File "init.py", line 357, in loads
return _default_decoder.decode(s)
File "json/decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "json/decoder.py", line 353, in raw_decode
obj, end = self.scan_once(s, idx)
...

Este tendo este erro ao tentar correr o api para C2B.