Compilation error with dyld "Image not found"

I’ve set up a basic project in Xcode with the OF project generator. I used the project generator to integrate 2 add ons into the project: ofxGUI and ofxFX. When I try to compile my app I get the following error:

dyld: Library not loaded: @executable_path/libfmodex.dylib
  Referenced from: /Users/satre/Developer/Projects/Art/String_Theory_OF/bin/String_Theory_OFDebug.app/Contents/MacOS/String_Theory_OFDebug
  Reason: image not found

What does this mean? Why am I getting this error?