LaTeX.org

I've stopped looking for a solution for the above mentioned errors. I simply returned to LyX 2.1.4 - and compilation runs smoothly!

Thanks to everyone who tried to help me! I think the next problem isn't far away. But for now I say: bye and thanks for the fish

...

You could post your .lyx file and additonally a pdfLaTeX export file here in the forum, as attachment to a post. (To protect the data, you could remove this attachment later on, or I can do for you)

Stefan

I've attached the master document of my book and the .tex-export in the LuaTeX ...

I'm hoping you have backups? If so, just look at the differences between the last backup that worked and the file now. Figure out which change caused the problems.

No, I have no backup. I tried to use the versioning system of LyX, but it failed.

The file I talked about didn't change at least for ...

LyX 2.2, MikTeX 2.9 updated today, Windows 7 32 bit

I'm working on a book. Compilation never failed up to now. Suddenly error messages concerning the LaTeX preamble appeared (see attachment) although I haven't changed anything in the preamble.

XeTeX-Error.png
LuaTeX-Error.png

The document ...