Why won't my project export to my droid?

I havnt had problems but now I’m getting the message
“Shader is using clip instruction (usually caused by alpha test). It might cause problems on some Qualcomm/Adreno drivers.

I have no idea what that means and not sure why it won’t run, it worked a couple days ago.

alright one of my sprites had “diffuse” as the shader. all fixed now.