Greeting vdog,
Hope you are doing well!
I found this information related with the error message you are facing:
Whenever data is sent back and forth from the Server, it is done in chunks. There is some overhead caused by the information exchanged between the Client and Server when negotiating the size of the chunks to be sent and when acknowledging the chunks sent and received. This is the chunking overhead. It is a feature of the HTTP protocol and the way in which data is sent back and forth between Client and Server.
Replay the script with WinInet option checked in Runtime settings. To enable this option, go to Runtime settings->Preferences-Advanced->WinInet Replay instead of Sockets.
Another information that has some relation with this issue, you can find it on this link: http://support.openview.hp.com/selfsolve/document/KM177179
Kindly waiting your reply!
Best Regards,
Alexis B