Factorio Forums

(Soz if its a duplicate, I swear I looked)
When clicking the green arrow on existing rails in order to build more off it, it doesnt align with the rail grid despite the rail definately fitting in there, as it was placed by blueprints previously.
it seems to mostly happen on angled rails(see photos), however it also seemed like when over building into already existing rails its acting like the space is blocked by something else (but soz forgot to screenshot that).

Thanks for the report. There are no bugs here.

As you can see, removed rail was a legacy rail (they were possible to built up to version 1.1, after that they are not buildable manually unless imported blueprints are used). Those rails had different alignment compared to new rails (that were introduced in version 2.0). Because of that if you try building new rails starting from an old rail they wont connect. Just remove more of the old rails and replace them with new rails.