diff --git a/addons/calendar/calendar_data.xml b/addons/calendar/calendar_data.xml
index 4435e8a4324..e1aad240292 100644
--- a/addons/calendar/calendar_data.xml
+++ b/addons/calendar/calendar_data.xml
@@ -212,7 +212,7 @@
                                                     <td colspan="3">
                                                        : 
                                                         % for attendee in object.event_id.attendee_ids:
-                                                            <div style='display:inline-block; border-radius: 50%; width:10px; height:10px;background:${ctx["color"][attendee.state]};'></div>
+                                                            <div style='display:inline-block; border-radius: 50%; width:10px; height:10px;background:${'color' in ctx and ctx["color"][attendee.state] or 'white'};'></div>
                                                             % if attendee.cn != object.cn:
                                                                 <span style="margin-left:5px">${attendee.cn}</span>
                                                             % else:
@@ -227,9 +227,9 @@
                                 </table>
                             </div>
                             <div style="height: auto;width:450px; margin:0 auto;padding-top:20px;padding-bottom:40px;">
-                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#8A89BA;margin : 0 15px 0 0;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/accept?db=${ctx['dbname']}&token=${object.access_token}&action=${ctx['action_id']}&id=${object.event_id.id}">Accept</a>
-                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#808080;margin : 0 15px 0 0;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/decline?db=${ctx['dbname']}&token=${object.access_token}&action=${ctx['action_id']}&id=${object.event_id.id}">Decline</a>
-                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#D8D8D8;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/view?db=${ctx['dbname']}&token=${object.access_token}&action=${ctx['action_id']}&id=${object.event_id.id}">View</a>
+                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#8A89BA;margin : 0 15px 0 0;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/accept?db=${'dbname' in ctx and ctx['dbname'] or ''}&token=${object.access_token}&action=${'action_id' in ctx and ctx['action_id'] or ''}&id=${object.event_id.id}">Accept</a>
+                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#808080;margin : 0 15px 0 0;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/decline?db=${'dbname' in ctx and ctx['dbname'] or '' }&token=${object.access_token}&action=${'action_id' in ctx and ctx['action_id'] or ''}&id=${object.event_id.id}">Decline</a>
+                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#D8D8D8;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/view?db=${'dbname' in ctx and ctx['dbname'] or ''}&token=${object.access_token}&action=${'action_id' in ctx and ctx['action_id'] or ''}&id=${object.event_id.id}">View</a>
                             </div> 
                         </div>
                     </body>
@@ -345,7 +345,7 @@
                                                     <td colspan="3">
                                                        : 
                                                         % for attendee in object.event_id.attendee_ids:
-                                                            <div style='display:inline-block; border-radius: 50%; width:10px; height:10px;background:${ctx["color"][attendee.state]};'></div>
+                                                            <div style='display:inline-block; border-radius: 50%; width:10px; height:10px;background:${'color' in ctx and ctx["color"][attendee.state] or 'white'};'></div>
                                                             % if attendee.cn != object.cn:
                                                                 <span style="margin-left:5px">${attendee.cn}</span>
                                                             % else:
@@ -360,9 +360,9 @@
                                 </table>                                      
                             </div>
                             <div style="height: auto;width:450px; margin:0 auto;padding-top:20px;padding-bottom:40px;">
-                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#8A89BA;margin : 0 15px 0 0;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/accept?db=${ctx['dbname']}&token=${object.access_token}&action=${ctx['action_id']}&id=${object.event_id.id}">Accept</a>
-                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#808080;margin : 0 15px 0 0;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/decline?db=${ctx['dbname']}&token=${object.access_token}&action=${ctx['action_id']}&id=${object.event_id.id}">Decline</a>
-                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#D8D8D8;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/view?db=${ctx['dbname']}&token=${object.access_token}&action=${ctx['action_id']}&id=${object.event_id.id}">View</a>
+                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#8A89BA;margin : 0 15px 0 0;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/accept?db=${'dbname' in ctx and ctx['dbname'] or ''}&token=${object.access_token}&action=${'action_id' in ctx and ctx['action_id'] or ''}&id=${object.event_id.id}">Accept</a>
+                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#808080;margin : 0 15px 0 0;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/decline?db=${'dbname' in ctx and ctx['dbname'] or ''}&token=${object.access_token}&action=${'action_id' in ctx and ctx['action_id'] or ''}&id=${object.event_id.id}">Decline</a>
+                                    <a style="padding: 8px 30px 8px 30px;border-radius: 6px;border: 1px solid #CCCCCC;background:#D8D8D8;text-decoration: none;color:#FFFFFF;" href="/calendar/meeting/view?db=${'dbname' in ctx and ctx['dbname'] or ''}&token=${object.access_token}&action=${'action_id' in ctx and ctx['action_id'] or ''}&id=${object.event_id.id}">View</a>
                             </div>                             
                         </div>
                     </body>
@@ -477,7 +477,7 @@
                                                     <td colspan="3">
                                                        : 
                                                         % for attendee in object.event_id.attendee_ids:
-                                                            <div style='display:inline-block; border-radius: 50%; width:10px; height:10px;background:${ctx["color"][attendee.state]};'></div>
+                                                            <div style='display:inline-block; border-radius: 50%; width:10px; height:10px;background:${'color' in ctx and ctx["color"][attendee.state] or 'white'};'></div>
                                                             % if attendee.cn != object.cn:
                                                                 <span style="margin-left:5px">${attendee.cn}</span>
                                                             % else: