Notices when editing a case activity and assigning to a contact and view activity shows array instead of assignee

Created a new case using the sample 'Housing Support' case type. Then edited the Medical Evaluation activity (from the Manage Case page) and added an assignee. Got the notices shown below. Also clicked activity subject to get Activity View pop-up and the "Assigned To" is displayed as 'Array Array' instead of the assignee name (screenshot attached).

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Notice: Undefined index: email in CRM_Case_Form_Activity->postProcess() (line 627 of /Users/dgg/git/crm_v4.4/CRM/Case/Form/Activity.php).
Notice: Undefined index: email in CRM_Case_Form_Activity->postProcess() (line 632 of /Users/dgg/git/crm_v4.4/CRM/Case/Form/Activity.php).
Warning: Illegal offset type in CRM_Case_XMLProcessor_Report->getActivity() (line 413 of /Users/dgg/git/crm_v4.4/CRM/Case/XMLProcessor/Report.php).
Warning: Illegal offset type in CRM_Case_XMLProcessor_Report->getActivity() (line 413 of /Users/dgg/git/crm_v4.4/CRM/Case/XMLProcessor/Report.php).
Notice: Array to string conversion in CRM_Case_XMLProcessor_Report->getActivity() (line 417 of /Users/dgg/git/crm_v4.4/CRM/Case/XMLProcessor/Report.php).
Notice: Array to string conversion in CRM_Case_XMLProcessor_Report->getActivity() (line 417 of /Users/dgg/git/crm_v4.4/CRM/Case/XMLProcessor/Report.php).
Notice: Undefined index: contact_id in CRM_Case_BAO_Case::sendActivityCopy() (line 1448 of /Users/dgg/git/crm_v4.4/CRM/Case/BAO/Case.php).