If you need more than two concurrent RDP sessions, here are legitimate alternatives:
Microsoft audits (common in enterprise and government) detect patched DLLs as a violation. Penalties can exceed the cost of proper RDS CALs by orders of magnitude. universal termsrv.dll patch windows server 2012 r2
If you cannot use automated tools (antivirus false positives), edit manually using HxD or similar hex editor. If you need more than two concurrent RDP
Note: Manual patching is error-prone. One wrong byte can break RDP entirely. Use an automated patcher whenever possible. Note: Manual patching is error-prone
The patch bypasses this fallback by altering the comparison instruction.