This sounds a lot like Debian bug #922608 [1] which is fixed in Eoan. Disco got modemmanager 1.10.0-1 on 2019-02-23, and Bionic got the backport on 2019-05-16.
Please try the version of modem-manager-gui from my PPA [2] and if this solves the problem we can prepare a Stable Release Update for Disco and Bionic. [1] https://bugs.debian.org/922608 [2] https://launchpad.net/~ginggs/+archive/ubuntu/sru ** Bug watch added: Debian Bug tracker #922608 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=922608 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1820130 Title: modem-manager-gui assert failure: munmap_chunk(): invalid pointer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/modem-manager-gui/+bug/1820130/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
