Hi Arash, > I installed my proposed change incl. comments from Stefan with commit > 22daed7c. With this commit, when I try to open any .tex file (existing or not), I get "(wrong-type-argument sequencep t)" errors like those in the attached backtrace (reproduced with emacs -Q). My TeX-master value is t. The patch below seems to do the trick (but I'll confess that I haven't studied the "big picture" here). Paul