Hi Laura
If you launch matisse from the Fudaa interface, you cannot add the -a option
The solution is to open a command windows, move to your work directory (with cd command) and there run "matisse -a"
Another solution (maybe a little more complex):
Edit the "runmatrub.pl" in the bin directory (it's a text file).
Search the following lines (arround line 560):
$langRun = ""; # langue codes
$langMsg = 0; # langue lanceur
Modify with
$langRun = " -a";
$langMsg = 1;
This second solution will allow you to launch matisse in english from the fudaa interface
Regards