Undefined control sequence error with pdflatex in Lyx 2.1.3

[duong nt]

I am running Ubuntu 12.04 with KDE desktop manager. I have LyX V2.1.3 and installed texlive-full. I have downloaded ClassicThesis-LyX-v4.1.zip, unzipped it, opened ClassicThesis.lyx in LyX and hit "Update" to generate a PDF (pdflatex) just to check if it works and get the following errors:

#!

Undefined control sequence:

 }
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."

#!


LaTeX Error: Missing \begin{document}.

 }

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.

Oddly enough, removing "Include: Chapter04.lyx" from Part III fixes the error, despite the document in question having the line "\begin_document" just like the other chapters.

I am pretty much a beginner in LaTeX so I have no idea what causes this. I've skimmed over the ClassicThesis-LyX-v4.1.pdf, the error reports here as well as dozens of error reports on google, but can't seem to pin down the cause.

[André Miede]

I am not familiar with LyX, but this seems like a rather generic error report. Some suggestions: * Maybe looking at the whole LyX error report helps. * Or to check your distribution, try compiling the classicthesis-LaTeX-version with pdflatex. * Another way to pinpoint the error might be deleting half of chapter 4, then another half until you find what causes the error.

[landroni]

I had seemingly the exact same error message when trying to compile ClassicThesis-LyX-v4.1 on Ubuntu Precise. From my checks, the TeX Live 2009 shipped with this Ubuntu version is simply too old for ClassicThesis-LyX-v4.1, and some packages need to be updated. I could easily update to TeX Live 2012 using TeX Live Backports PPA, and then ClassicThesis-LyX-v4.1 compiled without a fuss in LyX 2.1.4.

IMO this has nothing to do with classicthesis...