diff --git a/app/src/main/kotlin/com/wire/android/mapper/SystemMessageContentMapper.kt b/app/src/main/kotlin/com/wire/android/mapper/SystemMessageContentMapper.kt
index 4ffc5794908..bf262e2bacd 100644
--- a/app/src/main/kotlin/com/wire/android/mapper/SystemMessageContentMapper.kt
+++ b/app/src/main/kotlin/com/wire/android/mapper/SystemMessageContentMapper.kt
@@ -274,6 +274,7 @@ class SystemMessageContentMapper @Inject constructor(
                     FailedToAdd.Type.Federation -> UIMessageContent.SystemMessage.MemberFailedToAdd.Type.Federation
                     FailedToAdd.Type.LegalHold -> UIMessageContent.SystemMessage.MemberFailedToAdd.Type.LegalHold
                     FailedToAdd.Type.Unknown -> UIMessageContent.SystemMessage.MemberFailedToAdd.Type.Unknown
+                    FailedToAdd.Type.MissingKeyPackages -> UIMessageContent.SystemMessage.MemberFailedToAdd.Type.MissingKeyPackages
                 }
             )
 
diff --git a/app/src/main/kotlin/com/wire/android/ui/home/conversations/messages/item/SystemMessageItem.kt b/app/src/main/kotlin/com/wire/android/ui/home/conversations/messages/item/SystemMessageItem.kt
index fe8dadcdfcf..3908dcf8c1f 100644
--- a/app/src/main/kotlin/com/wire/android/ui/home/conversations/messages/item/SystemMessageItem.kt
+++ b/app/src/main/kotlin/com/wire/android/ui/home/conversations/messages/item/SystemMessageItem.kt
@@ -476,6 +476,7 @@ private fun SystemMessage.buildContent(isWireCellsEnabled: Boolean) = when (this
             Type.Federation -> R.string.url_message_details_offline_backends_learn_more
             Type.LegalHold -> R.string.url_legal_hold_learn_more
             Type.Unknown -> null
+            Type.MissingKeyPackages -> R.string.url_mls_learn_more
         }
     ) { expanded ->
         val markdownTextStyle = DefaultMarkdownTextStyle.copy(
@@ -492,6 +493,7 @@ private fun SystemMessage.buildContent(isWireCellsEnabled: Boolean) = when (this
                 Type.Federation -> R.plurals.label_system_message_conversation_failed_add_members_details_federation
                 Type.LegalHold -> R.plurals.label_system_message_conversation_failed_add_members_details_legal_hold
                 Type.Unknown -> R.plurals.label_system_message_conversation_failed_add_members_details_unknown
+                Type.MissingKeyPackages -> R.plurals.label_system_message_conversation_failed_add_members_details_missing_key_packages
             },
             count = memberNames.size,
             formatArgs = arrayOf(memberNames.limitList(expanded).toListMarkdownString())
diff --git a/app/src/main/kotlin/com/wire/android/ui/home/conversations/model/UIMessage.kt b/app/src/main/kotlin/com/wire/android/ui/home/conversations/model/UIMessage.kt
index 5b9df34c008..eeb3c390dc3 100644
--- a/app/src/main/kotlin/com/wire/android/ui/home/conversations/model/UIMessage.kt
+++ b/app/src/main/kotlin/com/wire/android/ui/home/conversations/model/UIMessage.kt
@@ -567,7 +567,7 @@ sealed interface UIMessageContent {
             val memberNames: List<UIText>,
             val type: Type,
         ) : SystemMessage {
-            enum class Type { Federation, LegalHold, Unknown; }
+            enum class Type { Federation, LegalHold, Unknown, MissingKeyPackages; }
         }
 
         @Serializable
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 2bfa85ba05c..02df86bf5de 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -276,6 +276,7 @@
     <string name="url_learn_about_search" translatable="false">https://support.wire.com/hc/articles/203121850</string>
     <string name="url_legal_hold_learn_more" translatable="false">https://support.wire.com/hc/articles/360002018278</string>
     <string name="url_message_details_offline_backends_learn_more" translatable="false">https://support.wire.com/hc/articles/9357718008093</string>
+    <string name="url_mls_learn_more" translatable="false">https://support.wire.com/hc/articles/12434725011485</string>
     <string name="url_message_details_reactions_learn_more" translatable="false">https://support.wire.com/hc/articles/212053645</string>
     <string name="url_message_details_read_receipts_learn_more" translatable="false">https://support.wire.com/hc/articles/360000665277</string>
     <string name="url_self_client_fingerprint_learn_more" translatable="false">https://support.wire.com/hc/articles/207692235</string>
@@ -873,6 +874,10 @@
         <item quantity="one">%1$s could not be added to the conversation.</item>
         <item quantity="other">%1$s could not be added to the conversation.</item>
     </plurals>
+    <plurals name="label_system_message_conversation_failed_add_members_details_missing_key_packages">
+        <item quantity="one">%1$s could not be added to the conversation. They may not have an MLS-capable client.</item>
+        <item quantity="other">%1$s could not be added to the conversation. They may not have MLS-capable clients.</item>
+    </plurals>
     <string name="label_system_message_conversation_degraded_mls">This conversation is no longer verified, as at least one participant started using a new device or has an invalid certificate.</string>
     <string name="label_system_message_conversation_degraded_proteus">This conversation is no longer verified, as at least one participant started using a new device or has an invalid certificate.</string>
     <string name="label_system_message_conversation_verified_mls">All devices are verified (end-to-end identity)</string>
diff --git a/kalium b/kalium
index ec51422c7c6..08d396ece05 160000
--- a/kalium
+++ b/kalium
@@ -1 +1 @@
-Subproject commit ec51422c7c6ccc3046699991853149b2153490ee
+Subproject commit 08d396ece058c5a3a2a77c96190916b8d2b5c06d