If you encounter errors with your WRE installation, here are some techniques to try when troubleshooting:

Setup Fails Due To MySQL
Setup failed saying it couldn't connect to mysql through /something/mysql.sock. This means that for some reason MySQL failed to start. See MySQL Fails To Start for more information. One of the most common causes of this during the setup is that you forgot to create a mysql user in your os.

MySQL Fails To Start
Check out the MySQL log to find out why. It can be found in /data/wre/var/mysqldata/*.err

Mod Perl Fails To Start
Check out the Mod Perl log to find out why. It can be found in /data/wre/var/logs/modperl.error.log. See also troubleshooting modperl.error.log

Mod Proxy Fails To Start
Check out the Mod Proxy log to find out why. It can be found in /data/wre/var/logs/modproxy.error.log. See also troubleshooting modproxy.error.log

Spectre Fails To Start
It could be that the upgrade didn't create the spectre config file in /data/WebGUI/etc. If not, you can create it yourself based upon spectre.conf.original that is found in the same folder. 

Why can I only get to the stats page?
You probably haven't set up your DNS for your web stats, and whatever new sites you've set up. Therefore, Apache is showing you the first site in its list, which is your stats.

Why do I get a bad gateway error?
This is usually caused by one of two things. Either, modproxy cannot resolve the hostname in order to get to the modperl site (check your DNS), or modperl is not started. Look in your process list to see if it's running. To start modperl do the following:

cd /data/wre/sbin
./wreservice.pl startmodperl