This two following case will crash if your station:
Zitat- There must be a path from at least one person node of the source terminal to at least one person node of the destination terminal.
- The path must be shorter than 350m
So all terminals in a station need to have at least a path to any other terminal, and this path need to be less than 350m
The reason why my underground station crashes when have 2 and 3 levels is now known.
UG told me in the next patch 350m will be 700m