http_process_state_early_100continue error

This is the HTTP profile telling you that the server's response was invalid in some manner. To fix it, you need to fix the server, however, at a push you could likely work around it by disabling the HTTP profile in an iRule ( HTTP::disable ) for the problematic URL.

Are you using an iRule on that virtual to perform an HTTP::collect at all ? If you're doing that, and the client is setting an Expect: header indicating it expects an HTTP/100 continue response, then that combination will produce this error message (and reset the clientside and serverside connections)

If you don't have any irule magic going on, then I suggest you get a tcpdump capture of the issue, and open a support ticket to investigate further