Do not click at any button inside F.A.R.L settings except those you know 100%what their functions are for. If you click on the save buttons above the READ button, you might break F.A.R.L but Save settings works perfect. Just be careful.

In my 2nd play through, my F.A.R.L got broken and I only got LUA errors and Try later messages in the command chat window. And I had clicked buttons I do not understand even 70% what their purpose are. It broke never the less. I was then only able to lay a one single track line.

In my 3rd play through, I just started F.A.R.L for the first time and I only made a copy of the 2 blueprintlayouts, added them inside my inventory (You must have them your backpack otherwise it fails, Very important) I added some wooden rails, signals and some large poles in the F.A.R.L wagon and:

JIPPIE - EVREKA - Praise the train LORD

...I managed to lay a perfect double track, left side traffic. It works.

I have read at least 4 different messages about that F.A.R.L give them LUA errors and I hope this workaround will be useful. Is it really a workaround? Well, do not touch anything that is not broken. Be careful about which button you actually click at, and that is my best advice. If you get a LUA error, try to uninstall F.A.R.L and its settings, restart the game from scratch, install FARL, restart the game again and login and try again. It might maybe work really. It should work. I am not sure if the settings do get deleted, but they should. When you start the game after you uninstalled it, do not accept that the game install FARL as it will notice that you run one less mod. Save the game ones without FARL installed in between, after the first restart of the game, which I forgot to add. So many steps...