Are you sure it is related to Qt 5.6.1? I have exactly the same versions of qt5-qtbase and akonadi here and it works fine.

Well I think the error states this clearly:
Cannot mix incompatible Qt library (version 0x50600) with this library (version 0x50601)

but what do I really know?

Did you perform a reboot after upgrade? Otherwise stuff started with 5.6.0 could be still running.

Did the upgrade in a VT, and then logged afterwards - must be sddm then - dam this is difficult..

Do not get this error after reboot, but both Kontact and korganizer shows "The Akonadi personal information management service is not operational"

So maybe it is not qt5 related :-)

Will open a new tricket if i can find what is not working...

FWIW, I'm seeing the very same problem after upgrading, and yes, this is after rebooting.

Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
QCommandLineParser: option not defined: "start-without-control"
Cannot mix incompatible Qt library (version 0x50600) with this library (version 0x50601)
"[\n0: akonadiserver(+0x178006) [0x557b183fe006]\n1: akonadiserver(+0x178320) [0x557b183fe320]\n2: /lib64/libc.so.6(+0x34770) [0x7f97ce0e3770]\n3: /lib64/libc.so.6(gsignal+0x35) [0x7f97ce0e36f5]\n4: /lib64/libc.so.6(abort+0x16a) [0x7f97ce0e52fa]\n5: /lib64/libQt5Core.so.5(+0x91471) [0x7f97cedaa471]\n6: /lib64/libQt5Core.so.5(_ZN14QObjectPrivateC1Ei+0x101) [0x7f97cef83361]\n7: /usr/lib64/qt5/plugins/sqldrivers/libqsqlite3.so(_ZN13QSQLiteDriverC2EP7QObject+0x3e) [0x7f97c0af2b1e]\n8: /usr/lib64/qt5/plugins/sqldrivers/libqsqlite3.so(+0xbcf5) [0x7f97c0af6cf5]\n9: /lib64/libQt5Sql.so.5(+0x195b6) [0x7f97cf52e5b6]\n10: /lib64/libQt5Sql.so.5(_ZN12QSqlDatabase11addDatabaseERK7QStringS2_+0x11) [0x7f97cf52eac1]\n11: akonadiserver(+0x27d81) [0x557b182add81]\n12: akonadiserver(+0x28f0c) [0x557b182aef0c]\n13: /lib64/libQt5Core.so.5(+0x277d16) [0x7f97cef90d16]\n14: /lib64/libQt5Core.so.5(_ZN7QObject5eventEP6QEvent+0x9b) [0x7f97cef85b8b]\n15: /lib64/libQt5Core.so.5(+0x24369a) [0x7f97cef5c69a]\n16: /lib64/libQt5Core.so.5(_ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent+0xaa) [0x7f97cef5c7aa]\n17: /lib64/libQt5Core.so.5(_ZN14QTimerInfoList14activateTimersEv+0x38b) [0x7f97cefab7ab]\n18: /lib64/libQt5Core.so.5(+0x292d01) [0x7f97cefabd01]\n19: /lib64/libglib-2.0.so.0(g_main_context_dispatch+0x163) [0x7f97ca610703]\n20: /lib64/libglib-2.0.so.0(+0x49ab0) [0x7f97ca610ab0]\n21: /lib64/libglib-2.0.so.0(g_main_context_iteration+0x2c) [0x7f97ca610b5c]\n22: /lib64/libQt5Core.so.5(_ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE+0x5f) [0x7f97cefac22f]\n23: /lib64/libQt5Core.so.5(_ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE+0xfa) [0x7f97cef5b5ea]\n24: /lib64/libQt5Core.so.5(_ZN16QCoreApplication4execEv+0x9c) [0x7f97cef6317c]\n25: akonadiserver(+0x26401) [0x557b182ac401]\n26: /lib64/libc.so.6(__libc_start_main+0xf1) [0x7f97ce0cf731]\n27: akonadiserver(_start+0x29) [0x557b182ace09]\n]\n"
ProcessControl: Application 'akonadiserver' returned with exit code 255 (Unknown error)
QCommandLineParser: option not defined: "start-without-control"
Cannot mix incompatible Qt library (version 0x50600) with this library (version 0x50601)
"[\n0: akonadiserver(+0x178006) [0x55a90c912006]\n1: akonadiserver(+0x178320) [0x55a90c912320]\n2: /lib64/libc.so.6(+0x34770) [0x7efe34d17770]\n3: /lib64/libc.so.6(gsignal+0x35) [0x7efe34d176f5]\n4: /lib64/libc.so.6(abort+0x16a) [0x7efe34d192fa]\n5: /lib64/libQt5Core.so.5(+0x91471) [0x7efe359de471]\n6: /lib64/libQt5Core.so.5(_ZN14QObjectPrivateC1Ei+0x101) [0x7efe35bb7361]\n7: /usr/lib64/qt5/plugins/sqldrivers/libqsqlite3.so(_ZN13QSQLiteDriverC2EP7QObject+0x3e) [0x7efe27726b1e]\n8: /usr/lib64/qt5/plugins/sqldrivers/libqsqlite3.so(+0xbcf5) [0x7efe2772acf5]\n9: /lib64/libQt5Sql.so.5(+0x195b6) [0x7efe361625b6]\n10: /lib64/libQt5Sql.so.5(_ZN12QSqlDatabase11addDatabaseERK7QStringS2_+0x11) [0x7efe36162ac1]\n11: akonadiserver(+0x27d81) [0x55a90c7c1d81]\n12: akonadiserver(+0x28f0c) [0x55a90c7c2f0c]\n13: /lib64/libQt5Core.so.5(+0x277d16) [0x7efe35bc4d16]\n14: /lib64/libQt5Core.so.5(_ZN7QObject5eventEP6QEvent+0x9b) [0x7efe35bb9b8b]\n15: /lib64/libQt5Core.so.5(+0x24369a) [0x7efe35b9069a]\n16: /lib64/libQt5Core.so.5(_ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent+0xaa) [0x7efe35b907aa]\n17: /lib64/libQt5Core.so.5(_ZN14QTimerInfoList14activateTimersEv+0x38b) [0x7efe35bdf7ab]\n18: /lib64/libQt5Core.so.5(+0x292d01) [0x7efe35bdfd01]\n19: /lib64/libglib-2.0.so.0(g_main_context_dispatch+0x163) [0x7efe31244703]\n20: /lib64/libglib-2.0.so.0(+0x49ab0) [0x7efe31244ab0]\n21: /lib64/libglib-2.0.so.0(g_main_context_iteration+0x2c) [0x7efe31244b5c]\n22: /lib64/libQt5Core.so.5(_ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE+0x5f) [0x7efe35be022f]\n23: /lib64/libQt5Core.so.5(_ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE+0xfa) [0x7efe35b8f5ea]\n24: /lib64/libQt5Core.so.5(_ZN16QCoreApplication4execEv+0x9c) [0x7efe35b9717c]\n25: akonadiserver(+0x26401) [0x55a90c7c0401]\n26: /lib64/libc.so.6(__libc_start_main+0xf1) [0x7efe34d03731]\n27: akonadiserver(_start+0x29) [0x55a90c7c0e09]\n]\n"
ProcessControl: Application 'akonadiserver' returned with exit code 255 (Unknown error)
QCommandLineParser: option not defined: "start-without-control"
Cannot mix incompatible Qt library (version 0x50600) with this library (version 0x50601)
"[\n0: akonadiserver(+0x178006) [0x5573fa54b006]\n1: akonadiserver(+0x178320) [0x5573fa54b320]\n2: /lib64/libc.so.6(+0x34770) [0x7f637ce17770]\n3: /lib64/libc.so.6(gsignal+0x35) [0x7f637ce176f5]\n4: /lib64/libc.so.6(abort+0x16a) [0x7f637ce192fa]\n5: /lib64/libQt5Core.so.5(+0x91471) [0x7f637dade471]\n6: /lib64/libQt5Core.so.5(_ZN14QObjectPrivateC1Ei+0x101) [0x7f637dcb7361]\n7: /usr/lib64/qt5/plugins/sqldrivers/libqsqlite3.so(_ZN13QSQLiteDriverC2EP7QObject+0x3e) [0x7f636f826b1e]\n8: /usr/lib64/qt5/plugins/sqldrivers/libqsqlite3.so(+0xbcf5) [0x7f636f82acf5]\n9: /lib64/libQt5Sql.so.5(+0x195b6) [0x7f637e2625b6]\n10: /lib64/libQt5Sql.so.5(_ZN12QSqlDatabase11addDatabaseERK7QStringS2_+0x11) [0x7f637e262ac1]\n11: akonadiserver(+0x27d81) [0x5573fa3fad81]\n12: akonadiserver(+0x28f0c) [0x5573fa3fbf0c]\n13: /lib64/libQt5Core.so.5(+0x277d16) [0x7f637dcc4d16]\n14: /lib64/libQt5Core.so.5(_ZN7QObject5eventEP6QEvent+0x9b) [0x7f637dcb9b8b]\n15: /lib64/libQt5Core.so.5(+0x24369a) [0x7f637dc9069a]\n16: /lib64/libQt5Core.so.5(_ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent+0xaa) [0x7f637dc907aa]\n17: /lib64/libQt5Core.so.5(_ZN14QTimerInfoList14activateTimersEv+0x38b) [0x7f637dcdf7ab]\n18: /lib64/libQt5Core.so.5(+0x292d01) [0x7f637dcdfd01]\n19: /lib64/libglib-2.0.so.0(g_main_context_dispatch+0x163) [0x7f6379344703]\n20: /lib64/libglib-2.0.so.0(+0x49ab0) [0x7f6379344ab0]\n21: /lib64/libglib-2.0.so.0(g_main_context_iteration+0x2c) [0x7f6379344b5c]\n22: /lib64/libQt5Core.so.5(_ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE+0x5f) [0x7f637dce022f]\n23: /lib64/libQt5Core.so.5(_ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE+0xfa) [0x7f637dc8f5ea]\n24: /lib64/libQt5Core.so.5(_ZN16QCoreApplication4execEv+0x9c) [0x7f637dc9717c]\n25: akonadiserver(+0x26401) [0x5573fa3f9401]\n26: /lib64/libc.so.6(__libc_start_main+0xf1) [0x7f637ce03731]\n27: akonadiserver(_start+0x29) [0x5573fa3f9e09]\n]\n"
ProcessControl: Application 'akonadiserver' returned with exit code 255 (Unknown error)
QCommandLineParser: option not defined: "start-without-control"
Cannot mix incompatible Qt library (version 0x50600) with this library (version 0x50601)
"[\n0: akonadiserver(+0x178006) [0x55ec5e544006]\n1: akonadiserver(+0x178320) [0x55ec5e544320]\n2: /lib64/libc.so.6(+0x34770) [0x7fb05ae0d770]\n3: /lib64/libc.so.6(gsignal+0x35) [0x7fb05ae0d6f5]\n4: /lib64/libc.so.6(abort+0x16a) [0x7fb05ae0f2fa]\n5: /lib64/libQt5Core.so.5(+0x91471) [0x7fb05bad4471]\n6: /lib64/libQt5Core.so.5(_ZN14QObjectPrivateC1Ei+0x101) [0x7fb05bcad361]\n7: /usr/lib64/qt5/plugins/sqldrivers/libqsqlite3.so(_ZN13QSQLiteDriverC2EP7QObject+0x3e) [0x7fb04d81cb1e]\n8: /usr/lib64/qt5/plugins/sqldrivers/libqsqlite3.so(+0xbcf5) [0x7fb04d820cf5]\n9: /lib64/libQt5Sql.so.5(+0x195b6) [0x7fb05c2585b6]\n10: /lib64/libQt5Sql.so.5(_ZN12QSqlDatabase11addDatabaseERK7QStringS2_+0x11) [0x7fb05c258ac1]\n11: akonadiserver(+0x27d81) [0x55ec5e3f3d81]\n12: akonadiserver(+0x28f0c) [0x55ec5e3f4f0c]\n13: /lib64/libQt5Core.so.5(+0x277d16) [0x7fb05bcbad16]\n14: /lib64/libQt5Core.so.5(_ZN7QObject5eventEP6QEvent+0x9b) [0x7fb05bcafb8b]\n15: /lib64/libQt5Core.so.5(+0x24369a) [0x7fb05bc8669a]\n16: /lib64/libQt5Core.so.5(_ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent+0xaa) [0x7fb05bc867aa]\n17: /lib64/libQt5Core.so.5(_ZN14QTimerInfoList14activateTimersEv+0x38b) [0x7fb05bcd57ab]\n18: /lib64/libQt5Core.so.5(+0x292d01) [0x7fb05bcd5d01]\n19: /lib64/libglib-2.0.so.0(g_main_context_dispatch+0x163) [0x7fb05733a703]\n20: /lib64/libglib-2.0.so.0(+0x49ab0) [0x7fb05733aab0]\n21: /lib64/libglib-2.0.so.0(g_main_context_iteration+0x2c) [0x7fb05733ab5c]\n22: /lib64/libQt5Core.so.5(_ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE+0x5f) [0x7fb05bcd622f]\n23: /lib64/libQt5Core.so.5(_ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE+0xfa) [0x7fb05bc855ea]\n24: /lib64/libQt5Core.so.5(_ZN16QCoreApplication4execEv+0x9c) [0x7fb05bc8d17c]\n25: akonadiserver(+0x26401) [0x55ec5e3f2401]\n26: /lib64/libc.so.6(__libc_start_main+0xf1) [0x7fb05adf9731]\n27: akonadiserver(_start+0x29) [0x55ec5e3f2e09]\n]\n"
ProcessControl: Application 'akonadiserver' returned with exit code 255 (Unknown error)
"akonadiserver" crashed too often and will not be restarted!

OK, re-opening.   So highlights of this last backtrace:

QCommandLineParser: option not defined: "start-without-control"
Cannot mix incompatible Qt library (version 0x50600) with this library (version 0x50601)

I suspect it's kf5-akonadi-server , and the
/usr/lib64/qt5/plugins/sqldrivers/libqsqlite3.so
plugin, though I'm still baffled why this issue is not reproducible

Ah, I *do* see in journalctl -b output, after issuing:
akonadictl restart:

QCommandLineParser: option not defined: "start-without-control"

but then it actually starts ok.

kdepim-16.04.3-1.fc24 kdepim-addons-16.04.3-1.fc24 kdepim-apps-libs-16.04.3-1.fc24 kdepim-runtime-16.04.3-1.fc24 kf5-akonadi-16.04.3-1.fc24 kf5-akonadi-calendar-16.04.3-1.fc24 kf5-akonadi-search-16.04.3-1.fc24 kf5-akonadi-server-16.04.3-2.fc24 kf5-calendarsupport-16.04.3-1.fc24 kf5-eventviews-16.04.3-1.fc24 kf5-gpgmepp-16.04.3-1.fc24 kf5-grantleetheme-16.04.3-1.fc24 kf5-incidenceeditor-16.04.3-1.fc24 kf5-kalarmcal-16.04.3-1.fc24 kf5-kblog-16.04.3-1.fc24 kf5-kcalendarcore-16.04.3-1.fc24 kf5-kcalendarutils-16.04.3-1.fc24 kf5-kcontacts-16.04.3-1.fc24 kf5-kdgantt2-16.04.3-1.fc24 kf5-kholidays-16.04.3-1.fc24 kf5-kidentitymanagement-16.04.3-1.fc24 kf5-kimap-16.04.3-1.fc24 kf5-kldap-16.04.3-1.fc24 kf5-kmailtransport-16.04.3-1.fc24 kf5-kmbox-16.04.3-1.fc24 kf5-kmime-16.04.3-1.fc24 kf5-kontactinterface-16.04.3-1.fc24 kf5-kpimtextedit-16.04.3-1.fc24 kf5-ktnef-16.04.3-1.fc24 kf5-libgravatar-16.04.3-1.fc24 kf5-libkdepim-16.04.3-1.fc24 kf5-libkleo-16.04.3-1.fc24 kf5-libksieve-16.04.3-1.fc24 kf5-mailcommon-16.04.3-1.fc24 kf5-mailimporter-16.04.3-1.fc24 kf5-messagelib-16.04.3-1.fc24 kf5-pimcommon-16.04.3-1.fc24 kf5-syndication-16.04.3-1.fc24 kleopatra-16.04.3-1.fc24 has been submitted as an update to Fedora 24. https://bodhi.fedoraproject.org/updates/FEDORA-2016-027969e889

Just occurred to me the only way to reproduce this would be to use the non-default sqlite akonadi backend (I was personally using mysql backend).  This newer kf5-akonadi-server build should fix that.

kdepim-16.04.3-1.fc24, kdepim-addons-16.04.3-1.fc24, kdepim-apps-libs-16.04.3-1.fc24, kdepim-runtime-16.04.3-1.fc24, kf5-akonadi-16.04.3-1.fc24, kf5-akonadi-calendar-16.04.3-1.fc24, kf5-akonadi-search-16.04.3-1.fc24, kf5-akonadi-server-16.04.3-2.fc24, kf5-calendarsupport-16.04.3-1.fc24, kf5-eventviews-16.04.3-1.fc24, kf5-gpgmepp-16.04.3-1.fc24, kf5-grantleetheme-16.04.3-1.fc24, kf5-incidenceeditor-16.04.3-1.fc24, kf5-kalarmcal-16.04.3-1.fc24, kf5-kblog-16.04.3-1.fc24, kf5-kcalendarcore-16.04.3-1.fc24, kf5-kcalendarutils-16.04.3-1.fc24, kf5-kcontacts-16.04.3-1.fc24, kf5-kdgantt2-16.04.3-1.fc24, kf5-kholidays-16.04.3-1.fc24, kf5-kidentitymanagement-16.04.3-1.fc24, kf5-kimap-16.04.3-1.fc24, kf5-kldap-16.04.3-1.fc24, kf5-kmailtransport-16.04.3-1.fc24, kf5-kmbox-16.04.3-1.fc24, kf5-kmime-16.04.3-1.fc24, kf5-kontactinterface-16.04.3-1.fc24, kf5-kpimtextedit-16.04.3-1.fc24, kf5-ktnef-16.04.3-1.fc24, kf5-libgravatar-16.04.3-1.fc24, kf5-libkdepim-16.04.3-1.fc24, kf5-libkleo-16.04.3-1.fc24, kf5-libksieve-16.04.3-1.fc24, kf5-mailcommon-16.04.3-1.fc24, kf5-mailimporter-16.04.3-1.fc24, kf5-messagelib-16.04.3-1.fc24, kf5-pimcommon-16.04.3-1.fc24, kf5-syndication-16.04.3-1.fc24, kleopatra-16.04.3-1.fc24 has been pushed to the Fedora 24 testing repository. If problems still persist, please make note of it in this bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2016-027969e889

The updated packages presently in testing resolved this problem for me. Thanks!

Works for me too. Thanks!

kdepim-16.04.3-1.fc24, kdepim-addons-16.04.3-1.fc24, kdepim-apps-libs-16.04.3-1.fc24, kdepim-runtime-16.04.3-1.fc24, kf5-akonadi-16.04.3-1.fc24, kf5-akonadi-calendar-16.04.3-1.fc24, kf5-akonadi-search-16.04.3-1.fc24, kf5-akonadi-server-16.04.3-2.fc24, kf5-calendarsupport-16.04.3-1.fc24, kf5-eventviews-16.04.3-1.fc24, kf5-gpgmepp-16.04.3-1.fc24, kf5-grantleetheme-16.04.3-1.fc24, kf5-incidenceeditor-16.04.3-1.fc24, kf5-kalarmcal-16.04.3-1.fc24, kf5-kblog-16.04.3-1.fc24, kf5-kcalendarcore-16.04.3-1.fc24, kf5-kcalendarutils-16.04.3-1.fc24, kf5-kcontacts-16.04.3-1.fc24, kf5-kdgantt2-16.04.3-1.fc24, kf5-kholidays-16.04.3-1.fc24, kf5-kidentitymanagement-16.04.3-1.fc24, kf5-kimap-16.04.3-1.fc24, kf5-kldap-16.04.3-1.fc24, kf5-kmailtransport-16.04.3-1.fc24, kf5-kmbox-16.04.3-1.fc24, kf5-kmime-16.04.3-1.fc24, kf5-kontactinterface-16.04.3-1.fc24, kf5-kpimtextedit-16.04.3-1.fc24, kf5-ktnef-16.04.3-1.fc24, kf5-libgravatar-16.04.3-1.fc24, kf5-libkdepim-16.04.3-1.fc24, kf5-libkleo-16.04.3-1.fc24, kf5-libksieve-16.04.3-1.fc24, kf5-mailcommon-16.04.3-1.fc24, kf5-mailimporter-16.04.3-1.fc24, kf5-messagelib-16.04.3-1.fc24, kf5-pimcommon-16.04.3-1.fc24, kf5-syndication-16.04.3-1.fc24, kleopatra-16.04.3-1.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.

closing (seems bodhi missed doing that automatically)