Thank, I found the issue, there was a \use_default_options false in the documentclass custom setting.
> ----- Original Message ----- > From: Jürgen Spitzmüller > Sent: 04/30/14 03:20 PM > To: Sean Patrick Burke > Subject: Re: lyx 2.1 > > 2014-04-30 14:50 GMT+02:00 Sean Patrick Burke: > > > > I just installed the nex lyx package > > > 3.13.10-200.fc20.x86_64 #1 SMP Mon Apr 14 20:34:16 UTC 2014 x86_64 > > x86_64 x86_64 GNU/Linux > > > > > > And I try to compile my document, > > > > > > and I get: > > > > > > \usepackage > > > [T1]{fontenc} > > > The control sequence at the end of the top line > > > of your error message was never \def'ed. If you have > > > misspelled it (e.g., `\hobx'), type `I' and the correct > > > spelling (e.g., `I\hbox'). Otherwise just continue, > > > and I'll forget about whatever was undefined. > > > > > > What is wrong? > > > with the previous version it was OK. > > > > > > > I’ve run into this when trying to import LyX 2.0 into LyX 2.1. Try copying > > and pasting the old document into a new document. > > > > This is a bad workaround (and you lose all document settings). > > Could one of you provide us with a test case? > > Jürgen =========================================================================== Patrick DUPRÉ | | email: pdu...@gmx.com Laboratoire de Physico-Chimie de l'Atmosphère | | Université du Littoral-Côte d'Opale | | Tel. (33)-(0)3 28 23 76 12 | | Fax: 03 28 65 82 44 189A, avenue Maurice Schumann | | 59140 Dunkerque, France ===========================================================================