latex reconfiguration needed after upgrade to 14.04

[zahtar]

Hello everyone!

Before upgrading to 14.04, I had a fully functional latex setup, with texmaker (4.1 installed via Muon), Xetex and various other packages. I had successfully created some pdfs with Texmaker, until February when I last needed to. On Tuesday I tried to use it once again but got an error: cannot start command.

I saved the settings to a file (I think/hope before making any changes) and have been experimenting ever since with the settings. All commands given through command line, like

apt-get install texlive-xetex

came with an answer that everything was up to date, no upgrade needed. I marked for purging the above mentioned package in Muon Package Manager to clear "settings residues" that might be incompatible with 14.04 or cause any kind of conflict and reinstalled. Now when trying to compile in Texmaker I get

! Fatal fontspec error: "cannot-use-pdftex"
!
! The fontspec package requires either XeTeX or LuaTeX to function.
!
! You must change your typesetting engine to, e.g., "xelatex" or "lualatex"
! instead of plain "latex" or "pdflatex".
!
! See the fontspec documentation for further information.

Having made a long research I get no results, and coming to a conclusion of an entire purge and reinstall. Before doing this (as described in the following link),
http://tex.stackexchange.com/questio...tall-on-ubuntu

I'd like to ask if there are any suggestions-ideas I could try

Thank you in advance