Solved
Railroad bug Green Valley
The new train bridge in the Green Valley is bugged. If you place a railroad connected to the bridge, and then try to remove the railroad it will leave behind 1 square of railroad which you now can’t ...
so, you accidentally deleted your railway bridge in Green Valley, too? DON'T PANIC!
This solution worked for me:
clear the area around the approaches to the bridges. delete the rail lines on the approaches to the bridges.then, leave to another region, like capital city or limestone cliffs or somethign, then return.
THEN try to draw the rail from the connectors of the bridge, back to the stations or where the railheads are. it should work!
Apparently, closing the game won't fix it (that just restores the rail to the bridge but doesn't fix the behaviour), nor will putting roads in front of it.. but swapping cities within your region does the trick!
