Short story: I've been using DITA-OT 1.5 for quite a while, and decided to try out switching to 2.0.1.
I've followed the install instructions on http://www.dita-ot.org/2.0/readme/installing-minimal-package-on-linux.html
I'm using xep as the fo processor (and have always been with prior dita ot versions).
running the sample pdf transform, I get this error:
[xep] Error: Could not find or load main class com.idiominc.ws.opentopic.fo.xep.Runner [xep] Java Result: 1
-(Note: the other transtypes I've tried, html, etc. seem to work fine)
The environment variables are set properly as far as I can tell, and apart from this issue: https://github.com/dita-ot/dita-ot/issues/1626 which seems to imply the problem was solved in 1.8.6, I haven't found any good indication of what this could mean.
Thanks for your help,