SuperTux version: System information: (details about your kernel, operating system, or distribution)
If available, please attach a backtrace of a crash (you can get one using GDB or another debugger), or a core dump. If you're on GNU/Linux and your distro is using systemd, it's highly likely that a core dump is available using coredumpctl(1)
.
If the issue only occurs in a custom level, please attach that too.