Hi,
The MaxExtractSize setting seems to be fine. BTW, sorry about parameter name being wrong on my part.
Log file does have error event by the AntiVirus engine component within SPE. Here's output from logconverter tool:
Wed Nov 12 23:22:00 JST 2014, The Symantec Protection Engine has encountered a scan error, Event Severity Level = Error, Scanner = AntiVirus, Result ID = 30, File name = D:\testFiles\largeFile_3GB.zip, Client IP = 127.0.0.1, Scan Duration (sec) = 834.148, Connect Duration (sec) = 834.508, Symantec Protection Engine IP address = 192.168.7.102, Symantec Protection Engine Port number = 1344, Uptime (in seconds) = 521527
The "Result ID = 30" part, I don't have information for, as the ID list I have is old and only have numbers up to 29.
In anycase, you should open a support case for the incident.
Regards,
Haro