violation of license policy

Hello, 
I just booted my PC and EmClient won’t go online and download mail. It says that I do not own a license, so I tried to activate again my free license and EmClient said to me that it is impossible to activate license in this PC because I have violated license policy.
I don’t know which issue is causing this, I’m synching just 2 accounts and until last friday EmClient was doing just fine.