API REST materialTransactions

Summary:

We are using API REST fscmRestApi/resources/11.13.18.05/materialTransactions, sometimes(right now is more frequently), that API responds with this error Code:

 "ErrorMessages": "1",

 "ErrorMessageNames": "1",

That Error not say to us what is real problem; we are reviewing data sending and all is correct, sometimes sending same data process end fine, but is not same behaviour in all events.

Where I can see meaning of this kind of errors, or log about that process?.

Regards