XenForo_Exception: Serialized value contains an object and this is not allowed

[Alpha1]

Im not 100% sure if this is caused by your addons or not:

XenForo_Exception: Serialized value contains an object and this is not allowed - library/XenForo/DataWriter/Helper/Denormalization.php:40
Generated By: xxx, Wednesday at 11:18 PM

Stack Trace
#0 /XenForo/DataWriter/Alert.php(86): XenForo_DataWriter_Helper_Denormalization::verifySerialized('a:4:{s:11:"prof...', Object(SV_AlertImprovements_XenForo_DataWriter_Alert), 'extra_data')
#1 /XenForo/DataWriter.php(995): XenForo_DataWriter_Alert->_verifyExtraData('a:4:{s:11:"prof...', Object(SV_AlertImprovements_XenForo_DataWriter_Alert), 'extra_data', Array)
#2 /XenForo/DataWriter.php(725): XenForo_DataWriter->_runVerificationCallback(Array, 'a:4:{s:11:"prof...', Array, 'extra_data')
#3 /XenForo/DataWriter.php(643): XenForo_DataWriter->_isFieldValueValid('extra_data', Array, 'a:4:{s:11:"prof...', Array)
#4 /OneSignal/Model/Alert.php(26): XenForo_DataWriter->set('extra_data', Array)
#5 /SV/UserTaggingImprovements/XenForo/Model/Alert.php(36): OneSignal_Model_Alert->alertUser(392018, 0, '', 'user', 392018, 'profile_post_de...', Array)
#6 /SV/DeadlockAvoidance/XenForo/Model/Alert.php(15): SV_UserTaggingImprovements_XenForo_Model_Alert->alertUser(392018, 0, '', 'user', 392018, 'profile_post_de...', Array)
#7 /XenForo/Model/Alert.php(425): SV_DeadlockAvoidance_XenForo_Model_Alert->alertUser(392018, 0, '', 'user', 392018, 'profile_post_de...', Array)
#8 /XenForo/Model/ProfilePost.php(1888): XenForo_Model_Alert::alert(392018, 0, '', 'user', 392018, 'profile_post_de...', Array)
#9 /XenForo/ControllerPublic/ProfilePost.php(190): XenForo_Model_ProfilePost->sendModeratorActionAlertForProfilePost('delete', Array, Array, 'Nope.')
#10 /XenForo/FrontController.php(369): XenForo_ControllerPublic_ProfilePost->actionDelete()
#11 /XenForo/FrontController.php(152): XenForo_FrontController->dispatch(Object(XenForo_RouteMatch))
#12 /index.php(13): XenForo_FrontController->run()
#13 {main}
Request State
array(3) {
["url"] => string(50) "https://forum.com/profile-posts/84850/delete"
["_GET"] => array(0) {
}
["_POST"] => array(6) {
["reason"] => string(5) "Nope."
["hard_delete"] => string(1) "0"
["send_author_alert"] => string(1) "1"
["author_alert_reason"] => string(5) "Nope."
["_xfConfirm"] => string(1) "1"
["_xfToken"] => string(8) "********"
}
}

 

[Xon]

I think this might be OneSignal, nothing I've added put objects into it.