This is very strange, we have Kemp doing forwarding and ssl for 2 servers on one ip, doing Http-->https. I did a reboot for the first time in a month or so, and now, on boot, one of the servers will work fine for a few minutes, the other doesn't work at all, and then after a couple minutes the first one dies too. the warning log shows nothing, and no changes have been made other than reboot.
the one that's always dead says err_invalid response
in the warning log i see this
Sending Redirect responses due to failed Real Servers
but when I look at real servers i see them both as up, and nothing has changed on either of them.