You can also make your own multiclient by editing Tibia.exe if you are having too many problems like me, to run many clients in one computer

This is not recommended though. If you do not know what you're doing and you may get banned.

Steps
  • Download any hex editor. I use this: HxD
  • Open Tibia.exe
  • Search for this hex string: FF 00 75 40 68
  • Change the 75 to EB
  • Save the file
  • Run as many clients as you need


Working for may versions. Even latest Tibia Client 10.13