[squid-users] Cache_peer breaks Squid 5.5

[HENDERSON, GAVEN L RTX]

Sorry if this has already been answered.  I couldn't find anything online regarding the problem I am experiencing.  I have a Squid server acting as a proxy relay.  It listens on two ports and, depending on which port a request comes in, the request is forwarded to a specific upstream proxy.  Everything was working prior to the 5.5 update.  Now, Squid starts but crashes a few seconds later.  I have traced it down to the cache_peer directives.  If I comment them out, the service is stable.  I have also tried the stock configuration with only the cache_peer directive added and it still crashes so I don't think the problem is being triggered by some other part of my configuration.  I'm not seeing anything particularly helpful in the messages log:

Nov 24 15:17:30 svr-squid squid[2259]: Squid Parent: squid-1 process 2290 exited due to signal 6 with status 0
Nov 24 15:17:30 svr-squid squid[2259]: Squid Parent: squid-1 process 2290 will not be restarted for 3600 seconds due to repeated, frequent failures
Nov 24 15:17:30 svr-squid squid[2259]: Exiting due to repeated, frequent failures
Nov 24 15:17:30 svr-squid systemd[1]: mailto:systemd-coredump at 21-2295-0.service: Deactivated successfully.
Nov 24 15:17:30 svr-squid systemd[1]: squid.service: Main process exited, code=exited, status=1/FAILURE
Nov 24 15:17:30 svr-squid systemd[1]: squid.service: Failed with result 'exit-code'.

Here is my configuration:

http_port 192.168.0.1:80 name=port80
http_port 192.168.0.1:81 name=port81

acl port80_acl myportname port80
acl port81_acl myportname port81
acl bypass_parent dstdom_regex "/etc/squid/bypass_parent.txt"
acl domain_blacklist dstdomain "/etc/squid/domain_blacklist.txt"

http_access deny all domain_blacklist
always_direct allow bypass_parent
never_direct allow port80_acl
never_direct allow port81_acl

cache_peer proxy1.domain.com parent 80 0 default name=proxy80
cache_peer_access proxy80 allow port80_acl
cache_peer_access proxy80 deny all

cache_peer proxy2.domain.com parent 80 0 default name=proxy81
cache_peer_access proxy81 allow port81_acl
cache_peer_access proxy81 deny all

http_access allow all

logformat squid [%tl] %>a %>eui %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt