Add another generator to the generators file
Catch exception if generator isn't found. And Fail

if the generator is missing from the file, then every element will be
popped. This fix catches this and prints an error message
Add FIXME flag to exception and fixed error code

only the correct exception should be caught in this way. Also the exit
code now indicates that there was an error.
do not print all the generators
do not print every decay result
add more generatos