diff --git a/launcher/launcher/src/main/java/sashegdev/zernmc/launcher/minecraft/launch/LaunchCommandBuilder.java b/launcher/launcher/src/main/java/sashegdev/zernmc/launcher/minecraft/launch/LaunchCommandBuilder.java
index 159ebde..bac9b69 100644
--- a/launcher/launcher/src/main/java/sashegdev/zernmc/launcher/minecraft/launch/LaunchCommandBuilder.java
+++ b/launcher/launcher/src/main/java/sashegdev/zernmc/launcher/minecraft/launch/LaunchCommandBuilder.java
@@ -36,15 +36,37 @@ public class LaunchCommandBuilder {
         }
         command.add("-Djava.library.path=" + nativesDir.toAbsolutePath());
 
+        String loaderType = instance.getLoaderType().toLowerCase();
+        boolean isModloader = "fabric".equals(loaderType) || "forge".equals(loaderType) || "neoforge".equals(loaderType);
+        
         VersionManifest manifest = resolveVersionManifest();
-        if (manifest != null) {
+        
+        // For modloaders, always use vanilla classpath with all libraries
+        if (isModloader) {
+            System.out.println(ZAnsi.cyan("  Modloader detected (" + loaderType + "), using vanilla classpath"));
             command.add("-cp");
-            command.add(buildClasspathFromManifest(manifest));
+            command.add(buildVanillaClasspath());
+            command.add(getVanillaMainClass());
+            command.addAll(getVanillaGameArguments(options));
+        } else if (manifest != null) {
+            String classpath = buildClasspathFromManifest(manifest);
+            
+            // Fallback if classpath is empty
+            if (classpath.isEmpty() || classpath.equals(instance.getPath().resolve("versions").resolve(getVersionId()).resolve(getVersionId() + ".jar").toAbsolutePath().toString())) {
+                System.out.println(ZAnsi.yellow("  manifest classpath пустой, использую vanilla classpath"));
+                command.add("-cp");
+                command.add(buildVanillaClasspath());
+                command.add(getVanillaMainClass());
+                command.addAll(getVanillaGameArguments(options));
+            } else {
+                command.add("-cp");
+                command.add(classpath);
 
-            String mainClass = resolveMainClass(manifest);
-            command.add(mainClass);
+                String mainClass = resolveMainClass(manifest);
+                command.add(mainClass);
 
-            command.addAll(resolveGameArguments(manifest, options));
+                command.addAll(resolveGameArguments(manifest, options));
+            }
         } else {
             command.add("-cp");
             command.add(buildVanillaClasspath());
diff --git a/launcher/launcher/src/resources/ui/launcher.js b/launcher/launcher/src/resources/ui/launcher.js
index 42f20d2..6edea1d 100644
--- a/launcher/launcher/src/resources/ui/launcher.js
+++ b/launcher/launcher/src/resources/ui/launcher.js
@@ -268,8 +268,10 @@ function startLogPolling() {
 
         // Game logs
         const gameResult = await apiCall('/game-logs');
+        console.log('[DEBUG] Game logs request:', gameResult.success, 'length:', gameResult.data ? gameResult.data.length : 0);
         if (gameResult.success && gameResult.data && gameResult.data.length > lastGameLogLength) {
             const newLogs = gameResult.data.substring(lastGameLogLength);
+            console.log('[DEBUG] New game logs:', newLogs.substring(0, 200));
             const lines = newLogs.split('\n').filter(l => l.trim());
             lines.forEach(line => {
                 log('[GAME] ' + line, 'info');