diff --git a/renderdoc/driver/vulkan/vk_core.h b/renderdoc/driver/vulkan/vk_core.h
index 2229c595c..1e9b4c7a2 100644
--- a/renderdoc/driver/vulkan/vk_core.h
+++ b/renderdoc/driver/vulkan/vk_core.h
@@ -257,6 +257,23 @@ struct VulkanActionCallback
                               VkCommandBuffer cmd) = 0;
 };
 
+struct UserDebugReportCallbackData
+{
+  VkInstance wrappedInstance;
+  VkDebugReportCallbackCreateInfoEXT createInfo;
+  bool muteWarned;
+
+  VkDebugReportCallbackEXT realObject;
+};
+
+struct UserDebugUtilsCallbackData
+{
+  VkDebugUtilsMessengerCreateInfoEXT createInfo;
+  bool muteWarned;
+
+  VkDebugUtilsMessengerEXT realObject;
+};
+
 class WrappedVulkan : public IFrameCapturer
 {
 private:
@@ -313,6 +330,11 @@ private:
   Threading::CriticalSection m_ThreadSerialisersLock;
   rdcarray<WriteSerialiser *> m_ThreadSerialisers;
 
+  Threading::CriticalSection m_CallbacksLock;
+  rdcarray<UserDebugReportCallbackData *> m_ReportCallbacks;
+  rdcarray<UserDebugUtilsCallbackData *> m_UtilsCallbacks;
+  void SendUserDebugMessage(const rdcstr &msg);
+
   uint64_t tempMemoryTLSSlot;
   struct TempMem
   {
diff --git a/renderdoc/driver/vulkan/wrappers/vk_device_funcs.cpp b/renderdoc/driver/vulkan/wrappers/vk_device_funcs.cpp
index 20d923b7b..320ab78ab 100644
--- a/renderdoc/driver/vulkan/wrappers/vk_device_funcs.cpp
+++ b/renderdoc/driver/vulkan/wrappers/vk_device_funcs.cpp
@@ -593,13 +593,14 @@ VkResult WrappedVulkan::vkCreateInstance(const VkInstanceCreateInfo *pCreateInfo
       VkDebugReportCallbackCreateInfoEXT *report =
           (VkDebugReportCallbackCreateInfoEXT *)pCreateInfo->pNext;
 
+      rdcstr msg = StringFormat::Fmt("RenderDoc does not support requested instance extension: %s.",
+                                     modifiedCreateInfo.ppEnabledExtensionNames[i]);
+
       while(report)
       {
         if(report->sType == VK_STRUCTURE_TYPE_DEBUG_REPORT_CALLBACK_CREATE_INFO_EXT)
-          report->pfnCallback(VK_DEBUG_REPORT_ERROR_BIT_EXT,
-                              VK_DEBUG_REPORT_OBJECT_TYPE_INSTANCE_EXT, 0, 1, 1, "RDOC",
-                              "RenderDoc does not support a requested instance extension.",
-                              report->pUserData);
+          report->pfnCallback(VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_INSTANCE_EXT,
+                              0, 1, 1, "RDOC", msg.c_str(), report->pUserData);
 
         report = (VkDebugReportCallbackCreateInfoEXT *)report->pNext;
       }
@@ -612,7 +613,7 @@ VkResult WrappedVulkan::vkCreateInstance(const VkInstanceCreateInfo *pCreateInfo
 
       messengerData.messageIdNumber = 1;
       messengerData.pMessageIdName = NULL;
-      messengerData.pMessage = "RenderDoc does not support a requested instance extension.";
+      messengerData.pMessage = msg.c_str();
       messengerData.sType = VK_STRUCTURE_TYPE_DEBUG_UTILS_MESSENGER_CALLBACK_DATA_EXT;
 
       while(messenger)
@@ -1583,6 +1584,34 @@ bool WrappedVulkan::SelectGraphicsComputeQueue(const rdcarray<VkQueueFamilyPrope
   return true;
 }
 
+void WrappedVulkan::SendUserDebugMessage(const rdcstr &msg)
+{
+  VkDebugUtilsMessengerCallbackDataEXT messengerData = {};
+
+  messengerData.messageIdNumber = 1;
+  messengerData.pMessageIdName = NULL;
+  messengerData.pMessage = msg.c_str();
+  messengerData.sType = VK_STRUCTURE_TYPE_DEBUG_UTILS_MESSENGER_CALLBACK_DATA_EXT;
+
+  {
+    SCOPED_LOCK(m_CallbacksLock);
+
+    for(UserDebugReportCallbackData *cb : m_ReportCallbacks)
+    {
+      cb->createInfo.pfnCallback(VK_DEBUG_REPORT_ERROR_BIT_EXT,
+                                 VK_DEBUG_REPORT_OBJECT_TYPE_DEVICE_EXT, 0, 1, 1, "RDOC",
+                                 msg.c_str(), cb->createInfo.pUserData);
+    }
+
+    for(UserDebugUtilsCallbackData *cb : m_UtilsCallbacks)
+    {
+      cb->createInfo.pfnUserCallback(VK_DEBUG_UTILS_MESSAGE_SEVERITY_ERROR_BIT_EXT,
+                                     VK_DEBUG_UTILS_MESSAGE_TYPE_GENERAL_BIT_EXT, &messengerData,
+                                     cb->createInfo.pUserData);
+    }
+  }
+}
+
 template <typename SerialiserType>
 bool WrappedVulkan::Serialise_vkCreateDevice(SerialiserType &ser, VkPhysicalDevice physicalDevice,
                                              const VkDeviceCreateInfo *pCreateInfo,
@@ -3678,10 +3707,20 @@ VkResult WrappedVulkan::vkCreateDevice(VkPhysicalDevice physicalDevice,
           "For KHR/EXT extensions file an issue on github to request support: "
           "https://github.com/baldurk/renderdoc");
 
+      SendUserDebugMessage(
+          StringFormat::Fmt("RenderDoc does not support requested device extension: %s.",
+                            createInfo.ppEnabledExtensionNames[i]));
+
       return VK_ERROR_EXTENSION_NOT_PRESENT;
     }
   }
 
+  if(m_Device != VK_NULL_HANDLE)
+  {
+    SendUserDebugMessage("RenderDoc does not support multiple simultaneous logical devices.");
+    return VK_ERROR_INITIALIZATION_FAILED;
+  }
+
   rdcarray<const char *> Extensions(createInfo.ppEnabledExtensionNames,
                                     createInfo.enabledExtensionCount);
 
diff --git a/renderdoc/driver/vulkan/wrappers/vk_misc_funcs.cpp b/renderdoc/driver/vulkan/wrappers/vk_misc_funcs.cpp
index 5d1bbbc17..027dde661 100644
--- a/renderdoc/driver/vulkan/wrappers/vk_misc_funcs.cpp
+++ b/renderdoc/driver/vulkan/wrappers/vk_misc_funcs.cpp
@@ -1757,15 +1757,6 @@ VkResult WrappedVulkan::vkCreateSamplerYcbcrConversion(
   return ret;
 }
 
-struct UserDebugReportCallbackData
-{
-  VkInstance wrappedInstance;
-  VkDebugReportCallbackCreateInfoEXT createInfo;
-  bool muteWarned;
-
-  VkDebugReportCallbackEXT realObject;
-};
-
 VkBool32 VKAPI_PTR UserDebugReportCallback(VkDebugReportFlagsEXT flags,
                                            VkDebugReportObjectTypeEXT objectType, uint64_t object,
                                            size_t location, int32_t messageCode,
@@ -1808,13 +1799,6 @@ VkBool32 VKAPI_PTR UserDebugReportCallback(VkDebugReportFlagsEXT flags,
   return user->createInfo.pfnCallback(flags, objectType, object, location, messageCode,
                                       pLayerPrefix, pMessage, user->createInfo.pUserData);
 }
-struct UserDebugUtilsCallbackData
-{
-  VkDebugUtilsMessengerCreateInfoEXT createInfo;
-  bool muteWarned;
-
-  VkDebugUtilsMessengerEXT realObject;
-};
 
 VkBool32 VKAPI_PTR UserDebugUtilsCallback(VkDebugUtilsMessageSeverityFlagBitsEXT messageSeverity,
                                           VkDebugUtilsMessageTypeFlagsEXT messageType,
@@ -1891,6 +1875,11 @@ VkResult WrappedVulkan::vkCreateDebugReportCallbackEXT(
     return vkr;
   }
 
+  {
+    SCOPED_LOCK(m_CallbacksLock);
+    m_ReportCallbacks.push_back(user);
+  }
+
   *pCallback = (VkDebugReportCallbackEXT)(uint64_t)user;
 
   return vkr;
@@ -1908,6 +1897,11 @@ void WrappedVulkan::vkDestroyDebugReportCallbackEXT(VkInstance instance,
 
   ObjDisp(instance)->DestroyDebugReportCallbackEXT(Unwrap(instance), user->realObject, pAllocator);
 
+  {
+    SCOPED_LOCK(m_CallbacksLock);
+    m_ReportCallbacks.removeOne(user);
+  }
+
   delete user;
 }
 
@@ -2314,6 +2308,11 @@ VkResult WrappedVulkan::vkCreateDebugUtilsMessengerEXT(
     return vkr;
   }
 
+  {
+    SCOPED_LOCK(m_CallbacksLock);
+    m_UtilsCallbacks.push_back(user);
+  }
+
   *pMessenger = (VkDebugUtilsMessengerEXT)(uint64_t)user;
 
   return vkr;
@@ -2331,6 +2330,11 @@ void WrappedVulkan::vkDestroyDebugUtilsMessengerEXT(VkInstance instance,
 
   ObjDisp(instance)->DestroyDebugUtilsMessengerEXT(Unwrap(instance), user->realObject, pAllocator);
 
+  {
+    SCOPED_LOCK(m_CallbacksLock);
+    m_UtilsCallbacks.removeOne(user);
+  }
+
   delete user;
 }