There is a freaking SUPER annoying bug in 2.47.
If you have a collision sensor and want to use it in a Python script, you can’t. No matter what I try, whenever I define a collision sensor in a Python script, the console ALWAYS says UNABLE TO FIND REQUESTED SENSOR. I know it’s not anything I’m doing wrong. I know Python and I know I’m doing everything correct.
Don’t believe me? Try it yourself.