Classic Client 6.3.12 For 64 Bits Fixed -

Understanding the Legacy: A Guide to Classic Client 6.3.12 for 64-bit Systems

Ensure your Classic Client is installed in the directory to prevent registry errors or permission conflicts with system-level 64-bit files. 2. Compatibility Settings classic client 6.3.12 for 64 bits

Even if you have DirectX 12, the classic client needs the old DLLs to render graphics correctly. Understanding the Legacy: A Guide to Classic Client 6