Thanks for your very nice words and extraordinary willingness to help the TC moodlers!
I am running the latest Moodle 2.6 and latest TC (Taskchain).
I can create a TC activity, I can modify it (using the admin settings).
I had it work with just one task and no condition.
Then I added one task (all HP) and a set of conditions to get to the second task
However at run time I got this (partially in French)
"Identifiant de module de cours non valide
Erreur de programmation dÃ©tectÃ©e. Ceci doit Ãªtre corrigÃ© par un programmeurÂ : The course you passed to $PAGE->set_cm does not correspond to the $cm."
PS: while upgrading to the latest TC there was this message:
but on a second try it went smoothly...