Authentication error

Follow what ScorpionVenom789 said, but even if error persit try this below:
Use "Revo Uninstaller Pro + Crack" and unistall BlackShot, this program will remove all registry from blackshot of your computer.
After this use "Ccleaner" run a clean & clean ur registry(important).
after this re-install BlackShot, re-start ur pc, re-start your internet then try play.
If error persist you can try install some programs that need for blackshot work properly, that is: Microsoft Visual C++ 2012 Redistributable (x86), NetFrameWork 4.5 or superior.

if you get this error, your account will be locked for 30 mins. try again 30 mins later or use another account