No KMail inbox after F23->F24 upgrade
Last July I upgraded from F23-nonproduct with KDE to F24-nonproduct with KDE using dnf-plugin-system-upgrade. With F23 there were 196 previously read messages stored in my KMail POP3 inbox. After the upgrade these messages were no longer visible in my inbox (although they were still on my system in ~/.local/share/.local-mail.directory). Also, after the upgrade, new email messages would be read but they would not appear in my inbox. After this problem occurred I tried to configure KMail to use ~/.local/share/.local-mail.directory as my inbox but my attempt was unsuccessful. What needs to be done to migrate KMail from F23 to F24?
Also, in F23 I had several weekly alarms configured in KAlarm. After the F23-> F24 upgrade these alarms disappeared.
Finally, on almost every daily F24 boot of my desktop PC I get a segment fault in QXcbEventReader and/or a segment fault in KActivitymanage.