diff --git a/app/src/main/java/org/linphone/ui/main/contacts/viewmodel/ContactViewModel.kt b/app/src/main/java/org/linphone/ui/main/contacts/viewmodel/ContactViewModel.kt
index 71c0c3154..e90988a89 100644
--- a/app/src/main/java/org/linphone/ui/main/contacts/viewmodel/ContactViewModel.kt
+++ b/app/src/main/java/org/linphone/ui/main/contacts/viewmodel/ContactViewModel.kt
@@ -180,12 +180,14 @@ class ContactViewModel
     private val contactsListener = object : ContactsManager.ContactsListener {
         @WorkerThread
         override fun onContactsLoaded() {
-            val friend = coreContext.contactsManager.findContactById(refKey)
-            if (friend != null && friend != this@ContactViewModel.friend) {
+            if (!::friend.isInitialized) return
+
+            val found = coreContext.contactsManager.findContactById(refKey)
+            if (found != null && found != friend) {
                 Log.i(
-                    "$TAG Found contact [${friend.name}] matching ref key [$refKey] after contacts have been loaded/updated"
+                    "$TAG Found contact [${found.name}] matching ref key [$refKey] after contacts have been loaded/updated"
                 )
-                this@ContactViewModel.friend = friend
+                friend = found
                 refreshContactInfo()
             }
         }
diff --git a/app/src/main/java/org/linphone/ui/main/history/viewmodel/HistoryViewModel.kt b/app/src/main/java/org/linphone/ui/main/history/viewmodel/HistoryViewModel.kt
index e89c6990c..5cc06ba3d 100644
--- a/app/src/main/java/org/linphone/ui/main/history/viewmodel/HistoryViewModel.kt
+++ b/app/src/main/java/org/linphone/ui/main/history/viewmodel/HistoryViewModel.kt
@@ -192,6 +192,7 @@ class HistoryViewModel
     @UiThread
     fun startAudioCall() {
         coreContext.postOnCoreThread { core ->
+            if (!::address.isInitialized) return@postOnCoreThread
             coreContext.startAudioCall(address)
         }
     }
@@ -199,6 +200,7 @@ class HistoryViewModel
     @UiThread
     fun startVideoCall() {
         coreContext.postOnCoreThread { core ->
+            if (!::address.isInitialized) return@postOnCoreThread
             coreContext.startVideoCall(address)
         }
     }
@@ -218,6 +220,8 @@ class HistoryViewModel
     @UiThread
     fun goToConversation() {
         coreContext.postOnCoreThread { core ->
+            if (!::address.isInitialized) return@postOnCoreThread
+
             val account = core.defaultAccount
             val localSipUri = account?.params?.identityAddress?.asStringUriOnly()
             if (!localSipUri.isNullOrEmpty()) {
@@ -315,9 +319,8 @@ class HistoryViewModel
     @UiThread
     fun goToMeetingWaitingRoom() {
         coreContext.postOnCoreThread {
-            if (::address.isInitialized) {
-                conferenceToJoinEvent.postValue(Event(address.asStringUriOnly()))
-            }
+            if (!::address.isInitialized) return@postOnCoreThread
+            conferenceToJoinEvent.postValue(Event(address.asStringUriOnly()))
         }
     }