Could you please try to get a full stacktrace of the crash, e.g. by running modemmanager through gdb, or maybe these instructions ensures it:
https://wiki.ubuntu.com/DebuggingModemmanager
Could you please try to get a full stacktrace of the crash, e.g. by running modemmanager through gdb, or maybe these instructions ensures it:
https:/ /wiki.ubuntu. com/DebuggingMo demmanager