diff --git a/packages/language-server/src/plugins/svelte/features/getDiagnostics.ts b/packages/language-server/src/plugins/svelte/features/getDiagnostics.ts
index f46158ea5..192622799 100644
--- a/packages/language-server/src/plugins/svelte/features/getDiagnostics.ts
+++ b/packages/language-server/src/plugins/svelte/features/getDiagnostics.ts
@@ -91,6 +91,13 @@ async function createParserErrorDiagnostic(error: any, document: Document) {
             document.scriptInfo || document.moduleScriptInfo
         );
 
+        if (!document.config?.preprocess && document.getText().includes('lang="')) {
+            Logger.error(
+                `Parsing ${document.getFilePath()} failed. No preprocess config found but lang tag exists. Skip showing error because they likely use other preprocessors.`
+            );
+            return [];
+        }
+
         if (isInStyle || isInScript) {
             diagnostic.message +=
                 '\n\nIf you expect this syntax to work, here are some suggestions: ';