Why does XML parsing error 110 occur when exchanging between 1C UT 10.3 and Bitrix 17.5.9?

Question

1C-Bitrix

Exchange module 7.0.1.5
In the exchange logs
on 03/12/2018 15:19:49--Uploading package 1 of user directories was NOT completed or completed with errors. NOT Uploaded 1,000 items.
03/12/2018 15:19:49--Start of unloading the package of 2 user directories
03/12/2018 15:19:54--Sending an authorization request.
03/12/2018 15:19:55--Sending an initialization request to determine the data exchange version.
2018/03/12 15:20:06--references___ca64aa1f-515c-43a1-98b8-5e0b5354dd2e.xml: An error occurred on the server side.
Server response:
failure
XML parsing error. Error code: 110.
I don't see any errors in the logs of the server itself.
Dear experts, tell me which way to dig and what kind of code is this? I can't find it on Google or I'm looking in the wrong place.