Hi uknut,
I'm a novice at this stuff, and I've never used the AHPreferenceActivity library before...
But, I found if I renamed your Module from Order to AnOrder, your initial error went away. Perhaps you used a reserved word? I had to change the StartActivity too.
But when I tried to compile your program after that I got a different error. I can only take a wild guess that they way you changed the example program for the library is wrong.
I noticed that you declare a variable called intentScreen that you never reference (not even initialise) but the equivalent variable in the library example program is used extensively.
Sorry I couldn't be of more help - perhaps we'll leave this to one of the B4A experts..