I'll have a go at using a sub-domain.
I'm looking in the default php.ini file at output_buffer as it was setup by ISPConfig. It has a value of 4096. Joomla is asking that I turn it off.
What do you recommend I do?
My VPS system:
(Ubuntu 14.04 LTS, Kernel 3.15.4-x86_64, Apache 2.4.7, MySQL 5.5.38, PHP 5.5.9, ISPConfig 188.8.131.52p5, Webmin, PureFTP & Quota, phpMyAdmin, postfix, dovecot, amavis, clamav, spamassassin, awstats, fail2ban, Jailkit, bind9, vlogger, webalizer)