Hi there!
Check that you have given executable permissions to the PAML programs inside the `bin` directory (if this is the directory where you have them). Also, make sure that they can run from a terminal! Last, make sure that the path that you are typing is the correct one and there are no typos.
Note that, to make the most out of the PAML programs, it is always best to run them from the terminal :)
All the best,
Sandra