SUMMARY

Can't access functionality "File -> Save As" at all after installing kdenlive with Snap on Ubuntu 18.04.  I get a long series of messages in console related to AppArmor.

STEPS TO REPRODUCE
1. sudo snap install kdenlive
2. start kdenlive on command line
3. try to save project (File -> Save As)

OBSERVED RESULT

Trying to do "File -> Save As" doesn't bring up any dialog, and gives a long list of messages in console, begining with:
QObject::connect: No such signal QDBusAbstractInterface::DeviceAdded(QString)
QObject::connect: No such signal QDBusAbstractInterface::DeviceRemoved(QString)
org.kde.solid.udisks2: Failed enumerating UDisks2 objects: "org.freedesktop.DBus.Error.AccessDenied"
 "An AppArmor policy prevents this sender from sending this message to this recipient; type=
\"method_call\", sender=\":1.134\" (uid=1000 pid=11124 comm=\"kdenlive \" label=\"snap.kdenlive.kdenlive (enforce)\") interface=\"org.freedesktop.DBus.Introspectable\" member=\"Introspect\" error name=\"(unset)\" requested_reply=\"0\" destination=\"org.freedesktop.UDisks2\" (uid=0 pid=1001 comm=\"/usr/lib/udisks2/udisksd \" label=\"unconfined\")"
org.kde.solid.udisks2: Failed enumerating UDisks2 objects: "org.freedesktop.DBus.Error.AccessDenied"

SOFTWARE/OS VERSIONS
18.04 Ubuntu Mate