I think I created what looks like a correct path, nothing is broken visually but the trains can not reach the interior stations.
I solved it by reconnecting the top and bottom semi-circle. They are actually two tiles too narrow but nothing indicates this visually.
Steps to reproduce:
1. Build the blueprint.
2. Take a train and tries to make it go to any of the innermost stations.
Blueprint
============
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
Correct looking but invalid train path
Re: Correct looking but invalid train path
There is no connection from any of the stations to the inner stations, the curved rails to it overlap because the radius is too small. There is a connection to it from the nearest vertical track so there is no open connection and no end of line track piece.
Re: Correct looking but invalid train path
Thank you very much for the explanation!