First download the Eset product here, like Internet security or other Eset products then follow these steps to activate your antivirus.
1.click on help and support
2.select “change license” or sometimes choose “enter license.”
3.click on “Use a purchased License key”
4. Here enter the license, you bought from iESET.
5. click on continue.
6.click on activate.
Your software activated
After activating, if this error is shown, contact support to check the problem.
Sometimes LiveGrid doesn’t work.