A Problem with General Relativity and Gravitational Lensing.

Gravitational lensing is said to be the bending of light caused by a gravity field.

A gravitational lens refers to a distribution of matter (such as a cluster of galaxies) between a distant source and an observer, that is capable of bending the light from the source, as it travels towards the observer. This effect is known as gravitational lensing and the amount of bending is one of the predictions of Albert Einstein's general theory of relativity.[1][2] (Classical physics also predicts bending of light, but only half that of general relativity's.[3])

For a light path to bend, light must have a force placed on the photon. 

Now if the photon has no mass, then either -

1) no force can be applied to bend the photon's flight path. For, F=ma, which means F= 0a = 0.

or

2) F=ma does not apply in relativity and the gravity field acts on the massless photon apart from F=ma. Yet such a mechanism is unknown to man. 

Hence, if a photon has no mass, the relativity claim that gravitational lensing occurs due to the bending of the space time continuum (S-T), infers the S-T bending acts on a photon in a superstitious or magical manner, apart from all known physics. Hence if a photon does not have mass, relativity is a physics theory that requires magic to account for bent photon flight paths.

But, if the photon has mass, then 

1) the S-T can bend the photons light path according to F=ma.

but then,

2) the photon cannot travel at c, for the mass of a particle at c is infinite according to the longitudinal mass = m/(1-v²/c²)³ = m/0. Likewise the energy of a photon would be infinite according to E = mc² / sqrt(1-v²/c²) = mc² /0.