For me when I tap on send I get the following popover dialog, when I select a sim it uses that one to send the message.
** Attachment added: "sim-select.png" https://bugs.launchpad.net/ubuntu/+source/messaging-app/+bug/1478610/+attachment/4434699/+files/sim-select.png -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1478610 Title: "No SIM card selected" blocks SMS reply To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/messaging-app/+bug/1478610/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs