What is the problem with this derivation

[Masterchess]

I am not sure why the files are out of order. I tried reordering them. But I numbered the papers one through four. I can also provide a LaTexed version of these equations. Somebody pointed out to me that an error in this math might be that E = mc^2 required that p = 0, and that therefore, S = 0. But I'm not sure that this is correct and they quite literally refuse to elaborate. 

Edited May 12, 2023 by Masterchess

[swansont]

2 hours ago, Masterchess said:

Somebody pointed out to me that an error in this math might be that E = mc^2 required that p = 0

Yes, the equation is E² = p²c² +m²c⁴

[Genady]

On p.1, 

E=hc/λ

is, presumably, energy of a photon. Two lines below,

E=mc²

is not energy of a photon.

These two E's are not the same thing.