UI: Show warning on plugin load failure

Allows the user to know what plugins failed to load. This is
particularly useful if we're going to block Qt5 plugins as well, or if
certain plugins can't load because they're incompatible with a newer
version.

UI/data/locale/en-US.ini

@@ -113,6 +113,10 @@ MoveSourceDown="Move Source(s) Down"
 SourceProperties="Open Source Properties"
 SourceFilters="Open Source Filters"
 
+# warning for plugin load failures
+PluginsFailedToLoad.Title="Plugin Load Error"
+PluginsFailedToLoad.Text="The following OBS plugins failed to load:\n\n%1\nPlease update or remove these plugins."
+
 # warning if program already open
 AlreadyRunning.Title="OBS is already running"
 AlreadyRunning.Text="OBS is already running! Unless you meant to do this, please shut down any existing instances of OBS before trying to run a new instance. If you have OBS set to minimize to the system tray, please check to see if it's still running there."

UI/window-basic-main.cpp

@@ -1778,15 +1778,18 @@ void OBSBasic::OBSInit()
 	LoadLibraryW(L"Qt6Network");
 #endif
 #endif
+	struct obs_module_failure_info mfi;
 
 	AddExtraModulePaths();
 	blog(LOG_INFO, "---------------------------------");
-	obs_load_all_modules();
+	obs_load_all_modules2(&mfi);
 	blog(LOG_INFO, "---------------------------------");
 	obs_log_loaded_modules();
 	blog(LOG_INFO, "---------------------------------");
 	obs_post_load_modules();
 
+	BPtr<char *> failed_modules = mfi.failed_modules;
+
 #ifdef BROWSER_AVAILABLE
 	cef = obs_browser_init_panel();
 #endif
@@ -2071,6 +2074,25 @@ void OBSBasic::OBSInit()
 	OnFirstLoad();
 
 	activateWindow();
+
+	/* ------------------------------------------- */
+	/* display warning message for failed modules  */
+
+	if (mfi.count) {
+		QString failed_plugins;
+
+		char **plugin = mfi.failed_modules;
+		while (*plugin) {
+			failed_plugins += *plugin;
+			failed_plugins += "\n";
+			plugin++;
+		}
+
+		QString failed_msg =
+			QTStr("PluginsFailedToLoad.Text").arg(failed_plugins);
+		OBSMessageBox::warning(this, QTStr("PluginsFailedToLoad.Title"),
+				       failed_msg);
+	}
 }
 
 void OBSBasic::OnFirstLoad()