OK, right to the question.

Is line of fire block from Character A to Character B in the diagram.

Legend
[ ] - Ground Clear terrain
[E] - Elevated Tarrain
[A] - Character A
[b] - Character B

[E][E][E][ ][ ][ ]
[E][b][E][ ][ ][ ]
[E][E][ ][ ][ ][ ]
[ ][ ][ ][ ][ ][ ]
[ ][ ][ ][ ][A][ ]
[ ][ ][ ][ ][ ][ ]

This comes from one of the Helicarrier Maps. Where B is sitting next in top of one of the planes. A took a power action to R/S to get a straight diagonal from B, but line of fire passes through two squares of elevated terrain. Is it block?

This question came up before I am sure, but I spent 20 minutes going through the search function but couldn't find anything. Thanks in advance for the help.

Page 14 of the rules:

LINE OF FIRE ACROSS
INTERSECTION POINTS
Whenever a character’s line of fire crosses exactly
through an intersection point, treat the point as the less
restrictive of the two squares that touch that point but
are not otherwise in the line of fire.

The LOF between A and B passes through an intersection with elevated terrain on either side of the point. Elevated terrain will normally block LOF (page 14, "A line of fire between
characters on different elevations is blocked by ... elevated terrain of any level higher than the level occupied by the character on the lower elevation, except the square occupied by the character on the higher elevation.") between characters on different elevation, so there is no "less restrictive" terrain type. LOF is just blocked.

Thank you Sir.

I appreciate your quick response. Rep to you for the hard work you, Rules Deputies, do.