kdeinit5 continuously generates errors

I’m experiencing some problems with kdeinit5, it generates a lot of errors classified as “critical” in systemd journal:

Jun 12 14:14:13 opensuse-kde kdeinit5[2817]: QDBusError::NoReply
Jun 12 14:14:13 opensuse-kde kdeinit5[2817]: "org.freedesktop.DBus.Error.NoReply"
Jun 12 14:14:13 opensuse-kde kdeinit5[2817]: "Message recipient disconnected from message bus without replying"
Jun 12 14:14:13 opensuse-kde kdeinit5[2817]: QDBusError::NoReply
Jun 12 14:14:13 opensuse-kde kdeinit5[2817]: "org.freedesktop.DBus.Error.NoReply"
Jun 12 14:14:13 opensuse-kde kdeinit5[2817]: "Message recipient disconnected from message bus without replying"
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: QDBusError::NoReply
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: "org.freedesktop.DBus.Error.NoReply"
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: "Message recipient disconnected from message bus without replying"
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: QDBusError::NoReply
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: "org.freedesktop.DBus.Error.NoReply"
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: "Message recipient disconnected from message bus without replying"
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: QDBusError::NoReply
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: "org.freedesktop.DBus.Error.NoReply"
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: "Message recipient disconnected from message bus without replying"
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: QDBusError::NoReply
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: "org.freedesktop.DBus.Error.NoReply"
Jun 12 14:14:15 opensuse-kde kdeinit5[2817]: "Message recipient disconnected from message bus without replying"
Jun 12 14:14:16 opensuse-kde kdeinit5[2817]: QDBusError::NoReply
Jun 12 14:14:16 opensuse-kde kdeinit5[2817]: "org.freedesktop.DBus.Error.NoReply"
Jun 12 14:14:16 opensuse-kde kdeinit5[2817]: "Message recipient disconnected from message bus without replying"

This happens continuously, and these errors are written in the system logs too, causing heavy disk usage and slowing down the system in a very noticeable way.

What are the causes of this problem? How can I solve this?