I was turning a 3-way double-rail junction into a 4-way junction. After adding the straight rails and one of the outlying curves, the game repeatedly crashed when I was adding a second outlying curve.

Logs and dumps attached.

When connecting to the Stress Test game organized by KoS and Caledorn, after the game has downloaded the whole map and was "catching up the changes", it crashed with an error message window.

Error log file (mentioned in the message) is attached.