I Have 2014 Subaru Forester-problems with push button start.new battery and new batteries in both FOB's. most of the time it works. It seems that the Eyesight dash light comes on when it does not work

if your programing the fob the following link will show you how if your doing the key can only program the remote part of it the key and start will need to be done at dealer the link also explains same
http://www.remotesremotes.com/v/vspfiles/photos/prog/subaru/su-p5e.pdf

Have you checked the power; on the fuses, the coil, the power regulator, and the battery?

Do headlights work? Do they get dim when you hit the start position, if so battery has bad cell.
Bad batteries might be OK after charging and running the car for a time but will discharge after car sits for maybe longer than a half hour. Usually a bad cell.
Take to auto parts store, they will load test it for free.

A common problem is the button switches on key fob circuit board have broken their soldering point. If you have (or know someone technical with) a FINE point soldering iron, the switches can be resoldered. This may not fix the your problem. If not, you need a new fob (try Amazon.com) Read up your owners manual on the procedure to reprogram the security system for new fobs. The process is tedious and usually takes some effort to the procedure to work.

Changed battery now running lights flash 2000 Forester Quick fix on mine use remote key fob lock door then unlock everything good no more flashing.

Maybe the button on your remote has crud on it?? If it's a sealed remote, it in all likelyhood, needs replacement.

Fuse box for forester 2014
1 under dash driver side left , and one under hood driver side next to battery
Thanks

I have a few trouble shooting tips for the problem with your Subaru Forester key fob.

1) Make sure you have the correct key fob part number. There are a couple different part numbers that are almost exactly the same.

2) Wipe the board
The board inside your remote can get a lot more filthy than you think! When the board is dirty it can prohibit the contact to the circuit board when you push down on the button. Simply wiping the circuit board off can make your key fob like new again!
3) The old car battery reset trick
I know this sounds absurd, but it works sometimes and is worth trying. If you exhausted all of the options above, disconnect bot terminals on your car battery for 10 minutes. Then reconnect them and try your key fob. This has worked for many people and I have no idea why. If you do, please comment below to explain.

4) Not sure where you bought the new key fob from, but some of the suppliers on eBay can be knock off quality. Try sending the one you purchased back and order one from here:
https://www.keylessentryremotefob.com/Subaru-Forester-Remotes-and-Keys-s/5381.htm

Here's a link to program your fobs,need to do both at the same time. 2008 Subaru Forester Key Fob Remote Programming Instructions

Not far fetched. The frequencies may bleed like a radio channel does when its not right on. Your two frequencies may be so close or one much stronger(other car) You should have it check before someone else notices it. Good luck