Why am I getting an error message when I try to load .tar.MD5 into Odin 3.09?

[AC Question]

Odin 3.09 Help

I can connect my device. I have the driver for the device. When I try to load the .tar.MD5 into Odin, it stops at "Check MD5.. Do not unplug the cable..". I cannot attempt to hit the start button because Odin stops responding. Some help, please!
Trying on a Galaxy S5 Active.