For some reason I started getting this crash when placing a new station even though I've placed many functioning stations (11 at this point). I had this happen once before, but managed to fix it. I think I might know what caused it so I will report back on that after I do a test.
Crash:

The mod SSPP Logistics Train Mod (0.4.9) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event SourceSinkPushPull::on_built_entity (ID 6)
LuaEntity API call when LuaEntity was invalid.
stack traceback:
[C]: in function 'index'
__SourceSinkPushPull/scripts/main/station.lua:55: in function 'try_create_station'
SourceSinkPushPull/scripts/main/station.lua:307: in function 'on_comb_broken'
SourceSinkPushPull/scripts/main/station.lua:341: in function 'destory_invalid_entities'
SourceSinkPushPull/scripts/main.lua:27: in function <SourceSinkPushPull/scripts/main.lua:14>

What I thought was causing it doesn't seem to be the issue. Also I found that I can't place any of the SSPP buildings now without that crash. Even tried copying a working station and still crash. Also did a few full game reloads, to no avail.