Impossible Rubik's cube position (2 corners swapped!)

Question

Left side, white up, Red, green, white corner swapped with Red, blue, white corner

Right side, white up, Red, blue, white corner swapped with Red, green, white corner

Right, Down, Back view of cube.

By Transposing the corners, it is possible to get all four corners in the correct orientation but the edges are at right angles to their correct sides. (View white up, left side.)

Transposed corners, Right, Down, Back view.

Same transpose but after U', Right top view

Again, Same transpose but after U', Left Down view

Solving this 8x8 cube, I ran into this impossible position. The white, red, green corner is swapped with the white, red, blue corner.

Note: It is impossible to cheat on this simulator...

So, the question is, "Is it really an impossible position? Or is the simulator flawed?"

Answer 1

The simulator is not flawed. This position is possible, but only on cubes 4x4 and up. One way to fix your cube is to perform the two edge swap parity case that only arises in larger cubes, like the picture below, taken from here. After you do that, your cube should be in a state that is solvable with regular 3x3 techniques.