diff --git a/LaunchServer/src/main/java/ru/gravit/launchserver/asm/ClassMetadataReader.java b/LaunchServer/src/main/java/ru/gravit/launchserver/asm/ClassMetadataReader.java
index 53cf3e89..c1f07859 100644
--- a/LaunchServer/src/main/java/ru/gravit/launchserver/asm/ClassMetadataReader.java
+++ b/LaunchServer/src/main/java/ru/gravit/launchserver/asm/ClassMetadataReader.java
@@ -23,7 +23,7 @@ private class CheckSuperClassVisitor extends ClassVisitor {
         String superClassName;
 
         public CheckSuperClassVisitor() {
-            super(Opcodes.ASM5);
+            super(Opcodes.ASM7);
         }
 
         @Override
@@ -57,10 +57,13 @@ public void acceptVisitor(String className, ClassVisitor visitor) throws IOExcep
 
     public byte[] getClassData(String className) throws IOException {
         for (JarFile f : cp) {
-            if (f.getEntry(className + ".class") != null)
+            if (f.getEntry(className + ".class") != null) {
+                byte[] bytes = null;
                 try (InputStream in = f.getInputStream(f.getEntry(className + ".class"))) {
-                    return IOHelper.read(in);
+                    bytes = IOHelper.read(in);
                 }
+                return bytes;
+            }
         }
         return IOHelper.read(IOHelper.getResourceURL(className + ".class"));
     }
diff --git a/LaunchServer/src/main/java/ru/gravit/launchserver/manangers/NodeTransformer.java b/LaunchServer/src/main/java/ru/gravit/launchserver/manangers/NodeTransformer.java
index 59dbd2b4..f90f0a1d 100644
--- a/LaunchServer/src/main/java/ru/gravit/launchserver/manangers/NodeTransformer.java
+++ b/LaunchServer/src/main/java/ru/gravit/launchserver/manangers/NodeTransformer.java
@@ -33,7 +33,7 @@ public byte[] transform(byte[] input, String classname, JARLauncherBinary data)
         ClassNode cn = new ClassNode();
         cr.accept(cn, ClassReader.SKIP_DEBUG);
         for (ClassNodeTransformer tr : transLst) tr.transform(cn, classname, data);
-        ClassWriter cw = new SafeClassWriter(data.reader, ClassWriter.COMPUTE_FRAMES);
+        ClassWriter cw = new SafeClassWriter(data.reader, ClassWriter.COMPUTE_MAXS);
         cn.accept(cw);
         return cw.toByteArray();
     }