diff --git a/src/Bundle/ChillCalendarBundle/Form/CalendarType.php b/src/Bundle/ChillCalendarBundle/Form/CalendarType.php
index 05dc362b4..560d12a40 100644
--- a/src/Bundle/ChillCalendarBundle/Form/CalendarType.php
+++ b/src/Bundle/ChillCalendarBundle/Form/CalendarType.php
@@ -131,6 +131,9 @@ class CalendarType extends AbstractType
                     return implode(',', $personIds);
                 },
                 function (?string $personsAsString): array {
+                    if (null === $personsAsString) {
+                        return [];
+                    }
                     return array_map(
                         fn (string $id): ?Person => $this->om->getRepository(Person::class)->findOneBy(['id' => (int) $id]),
                         explode(',', $personsAsString)
@@ -151,6 +154,9 @@ class CalendarType extends AbstractType
                     return implode(',', $thirdpartyIds);
                 },
                 function (?string $thirdpartyAsString): array {
+                    if (null === $thirdpartyAsString) {
+                        return [];
+                    }
                     return array_map(
                         fn (string $id): ?ThirdParty => $this->om->getRepository(ThirdParty::class)->findOneBy(['id' => (int) $id]),
                         explode(',', $thirdpartyAsString)
@@ -230,6 +236,7 @@ class CalendarType extends AbstractType
 
     public function getBlockPrefix()
     {
-        return 'chill_calendarbundle_calendar';
+        // as the js share some hardcoded items from activity, we have to rewrite block prefix
+        return 'chill_activitybundle_activity';
     }
 }
diff --git a/src/Bundle/ChillCalendarBundle/Resources/config/services.yml b/src/Bundle/ChillCalendarBundle/Resources/config/services.yml
index bdfaf413f..4dcda0fd8 100644
--- a/src/Bundle/ChillCalendarBundle/Resources/config/services.yml
+++ b/src/Bundle/ChillCalendarBundle/Resources/config/services.yml
@@ -29,3 +29,8 @@ services:
         arguments:
             $azure: '@knpu.oauth2.provider.azure'
         tags: ['console.command']
+        
+    Chill\CalendarBundle\Security\:
+        autoconfigure: true
+        autowire: true
+        resource: '../../Security/'
diff --git a/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store.js b/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store.js
index db2950bd4..a0d5a8715 100644
--- a/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store.js
+++ b/src/Bundle/ChillCalendarBundle/Resources/public/vuejs/Calendar/store.js
@@ -34,7 +34,8 @@ const store = createStore({
    strict: debug,
    state: {
      activity: mapEntity(window.entity), // activity is the calendar entity actually
-     currentEvent: null
+     currentEvent: null,
+     availableLocations: [],
    },
    getters: {
       suggestedEntities(state) {
@@ -58,6 +59,10 @@ const store = createStore({
            .filter(p => !existingPersonIds.includes(p.id))
        },
       suggestedRequestor(state) {
+        if (state.activity.accompanyingPeriod.requestor === null) {
+            return [];
+        }
+
         const existingPersonIds = state.activity.persons.map(p => p.id);
         const existingThirdPartyIds = state.activity.thirdParties.map(p => p.id);
         return [state.activity.accompanyingPeriod.requestor]
@@ -67,11 +72,14 @@ const store = createStore({
           );
       },
       suggestedUser(state) {
-        const existingUserIds = state.activity.users.map(p => p.id);
-        return [state.activity.accompanyingPeriod.user]
-          .filter(
-            u => !existingUserIds.includes(u.id)
-          );
+          if (null === state.activity.users) {
+              return [];
+          }
+          const existingUserIds = state.activity.users.map(p => p.id);
+          return [state.activity.accompanyingPeriod.user]
+            .filter(
+              u => u !== null && !existingUserIds.includes(u.id)
+            );
       },
       suggestedResources(state) {
         const resources = state.activity.accompanyingPeriod.resources;
@@ -132,15 +140,15 @@ const store = createStore({
          console.log('### action addPersonsInvolved', payload.result.type);
          switch (payload.result.type) {
             case 'person':
-               let aPersons = document.getElementById("chill_calendarbundle_calendar_persons");
+               let aPersons = document.getElementById("chill_activitybundle_activity_persons");
                aPersons.value = addIdToValue(aPersons.value, payload.result.id);
                break;
             case 'thirdparty':
-               let aThirdParties = document.getElementById("chill_calendarbundle_calendar_professionals");
+               let aThirdParties = document.getElementById("chill_activitybundle_activity_professionals");
                aThirdParties.value = addIdToValue(aThirdParties.value, payload.result.id);
                break;
             case 'user':
-               let aUsers = document.getElementById("chill_calendarbundle_calendar_invites");
+               let aUsers = document.getElementById("chill_activitybundle_activity_invites");
                aUsers.value = addIdToValue(aUsers.value, payload.result.id);
                break;
          };
@@ -150,15 +158,15 @@ const store = createStore({
          //console.log('### action removePersonInvolved', payload);
          switch (payload.type) {
             case 'person':
-               let aPersons = document.getElementById("chill_calendarbundle_calendar_persons");
+               let aPersons = document.getElementById("chill_activitybundle_activity_persons");
                aPersons.value = removeIdFromValue(aPersons.value, payload.id);
                break;
             case 'thirdparty':
-               let aThirdParties = document.getElementById("chill_calendarbundle_calendar_professionals");
+               let aThirdParties = document.getElementById("chill_activitybundle_activity_professionals");
                aThirdParties.value = removeIdFromValue(aThirdParties.value, payload.id);
                break;
             case 'user':
-               let aUsers = document.getElementById("chill_calendarbundle_calendar_invites");
+               let aUsers = document.getElementById("chill_activitybundle_activity_invites");
                aUsers.value = removeIdFromValue(aUsers.value, payload.id);
                break;
          };
@@ -168,23 +176,23 @@ const store = createStore({
       // Calendar
       createEvent({ commit }, payload) {
          console.log('### action createEvent', payload);
-         let startDateInput = document.getElementById("chill_calendarbundle_calendar_startDate");
+         let startDateInput = document.getElementById("chill_activitybundle_activity_startDate");
          startDateInput.value = payload.startStr;
-         let endDateInput = document.getElementById("chill_calendarbundle_calendar_endDate");
+         let endDateInput = document.getElementById("chill_activitybundle_activity_endDate");
          endDateInput.value = payload.endStr;
-         let mainUserInput = document.getElementById("chill_calendarbundle_calendar_mainUser");
+         let mainUserInput = document.getElementById("chill_activitybundle_activity_mainUser");
          mainUserInput.value = payload.users.logged.id;
          commit('setEvents', payload);
       },
       updateEvent({ commit }, payload) {
          console.log('### action updateEvent', payload);
-         let startDateInput = document.getElementById("chill_calendarbundle_calendar_startDate");
+         let startDateInput = document.getElementById("chill_activitybundle_activity_startDate");
          startDateInput.value = payload.event.start.toISOString();
-         let endDateInput = document.getElementById("chill_calendarbundle_calendar_endDate");
+         let endDateInput = document.getElementById("chill_activitybundle_activity_endDate");
          endDateInput.value = payload.event.end.toISOString();
-         let calendarRangeInput = document.getElementById("chill_calendarbundle_calendar_calendarRange");
+         let calendarRangeInput = document.getElementById("chill_activitybundle_activity_calendarRange");
          calendarRangeInput.value = Number(payload.event.extendedProps.calendarRangeId);
-         let mainUserInput = document.getElementById("chill_calendarbundle_calendar_mainUser");
+         let mainUserInput = document.getElementById("chill_activitybundle_activity_mainUser");
          mainUserInput.value = Number(payload.event.source.id);
          commit('setEvents', payload);
       },
@@ -192,7 +200,7 @@ const store = createStore({
       // Location
       updateLocation({ commit }, value) {
          console.log('### action: updateLocation', value);
-         let hiddenLocation = document.getElementById("chill_calendarbundle_calendar_location");
+         let hiddenLocation = document.getElementById("chill_activitybundle_activity_location");
          if (value.onthefly) {
              const body = {
                  "type": "location",