Flans mod TaskExecutionError during compile for modern warfare-content pack-1.7.2-4.2.jar

I am receiving a TaskExecutionError stating it “doesn’t exist” for a jar from flans mod during compiling, the file specifically is the modern warfare-content pack-1.7.2-4.2.3.jar. The version of gradle is GRADLE-1.11

(I didn’t change a thing in the code)

Should I also post this on the flans website?

Yes, please ask the authors/maintainers of the build.