Move the window over far enough that the railing will clear it and the trim. It shouldn't be anything the framers can't handle. Is there any interior reason that it can't be moved?

If there is, move the offending side over, while keeping the other one where it is. The window will be slightly narrower, but the problem will be solved.

Adjust the upstairs window to match.

You could also just narrow the window until it clears the railing, leaving it centered in its current location. Then you wouldn't need to change the upstairs window.

Thank you for the suggestions! I should have mentioned that the window can't be moved over because of being centred on bulkheads and lining up with other windows on the interior. Also, it is too late to make the window smaller - they are arriving next week.

I think we are going to try to start the railing so it clears the window and trim and just have a little jog in the deck to allow for the window. The columns will still block the view a bit but I don't think there is much else that can be done. Hopefully, with the jog in the deck, it won't look too odd.

Couldn't you put a curve in the railing? Have it start straight back from the post and then have it curve so it clears the window.

"I should have mentioned that the window can't be moved over because of being centred on bulkheads and lining up with other windows on the interior."

I think not having the window centered on the porch area is going to look strange.

You could extend the porch a foot or more farther out in the last bay next to the house so the railing misses the window. Making it look good is a matter of careful detailing. A hundred years ago builders were highly skilled at this kind of work but today everything has to be conventional or no one can or wants to do it.

Would it be possible to put stairs from the porch right along that wall? Then maybe you could stop the railing before you got to the window and have stairs there.

Maybe you could build in a bench and/or planter into the jog. That would make it look like a design detail instead of a mistake.

How far is it from the window to that nearest post in front of the window? If it is not too wide a distance, I think the idea of placing a set of steps between the post and the window is your best bet.

If the steps will be less than 44", I think you can get away with only having a handrail on one side... the side away from the window. (Check with your local building code to verify the maximum width stair allowable without requiring handrails on both sides.)

Then, if the steps are wide enough, place small potted plants along the wall-side of the steps and no one would ever wonder why there is no railing on that side and therefore will not notice that the window would have gotten in the way of a railing.

Bevangel and I sometimes think alike!
I was going to suggest to do some sort of an "exit" to that end of the porch so you do not have to extend the railing to the wall/window. It looks like you have about 4' wich is the perfect width (my guess is, your trusses are at 2' on center). If it is more than that, you can built an "L" shape railing part of the L attached to the column and the other end going down to the steps.

Do not worry too much. It is not the end of the world and I have seen this happening before.