SketchUp can refuse to load an unsigned extension. Railworks installs through Extension Manager; you have to allow it once.
Who this applies to
Installs that finish without error but never show a Railworks toolbar or menu, or installs that warn about an unsigned extension.
Set the loading policy
- Open Extensions → Extension Manager.
- Find the loading policy control (Unrestricted / Approve / similar, depending on SketchUp version).
- Set it so unapproved extensions can load, then Approve Railworks if SketchUp lists it.
- Enable Railworks if the switch is off.
- Restart SketchUp.
When to contact support
If the policy is already Unrestricted and Railworks is enabled, include a screenshot of Extension Manager.