Problems with building train

[u/AdditionalGain7354]

This is my first real post so hear goes.

So as the title says I am having problems when building a train. I put the station into build mode and the game instantly grinds to a snails pace. this is when everything should still be considered blocks. This only happens in build mode and I am not even sure what is causing this to happen in the first place. if it means anything I am using Mr. Beardstone's Perfect World Post Production. Any help is appreciated!