We went from a server running 14.04 to 16.04.1. It took some work but it is running. The final solution was:
1. Dump of the database 2. Completely clean install and set up of RT on the new server (from RT directly, not from a repository). I tested this and saw it worked. The old server had RT set up to use mod_perl2. We now use mod_cfgid which seemed to be the default. 3. Restored the database. In our case we went from RT 4.0.x to RT 4.4.1 so at this point I used the steps to upgrade the DB. Things are working well so far. I hope this helps
--------- RT 4.4 and RTIR training sessions, and a new workshop day! https://bestpractical.com/training * Boston - October 24-26 * Los Angeles - Q1 2017
