Fortify - Apex Scan

I am trying to run a scan with 17.10 on an Apex code base. I followed the instructions in the User guide but am having issues extracting the custom objects from Salesforce. When I run the sf_extractor tool, I get the following error message: 

Connecting to of sobjects: 574
Number of sobjects to process: 573
Number of sobjects to process: 572
Number of sobjects to process: 571 Failed to send request to https://*redacted**redacted*

at com.sforce.soap.partner.PartnerConnection.describeSObject(
at SObjectExtractor.retrieveInfo(Unknown Source)
at SObjectExtractor.main(Unknown Source)
Caused by: Unexpected end of ZLIB input stream

Has anyone else encountered this issue?