I have received error 105 - Communication Error in my response. What does it mean?

Error 105 in our system is classified as a Communication error.

This error is caused when the connection with the Seller's system has been refused and we were not able to establish a connection with their system. 

If those errors have suddenly appeared, we recommend contacting the Seller in order to figure out if they have any issues at their end (servers crash), and check that the URLs of your Seller configurations are right.