Arduino not responding to Processing/TouchOSC

I have an Arduino Uno and before I had been able to use processing with the TouchOSC app to control some servos and run some sketches with both Arduino and Processing. However, I now have been unable to communicate with the Arduino using Processing and the TouchOSC app. Processing and the TouchOSC app are working fine and values are being delivered to the console in Processing, but Arduino does not respond at all. Has anyone had any problems like this before or know of any solutions? Any help would be appreciated

Has anyone had any problems like this before

Yes.

know of any solutions?

Make sure the Arduino is connected to the port that Processing thinks it is (or, more accurately, make sure Processing uses the port that the Arduino is connected to).

Make sure that the baud rates are the same, in the Processing and Arduino sketches.

Make sure that the Arduino sketch is programmed to deal with serial input.