This error message is displayed if the license file has been corrupted.
This could be due to it being transferred in ASCII mode rather than binary or an incomplete file.
Delete the keystore by using the option from the Windows Start menu >> All Programs >> Locklizard >> Lizard “product name” >> Remove Keystore (where “product name” is the name of the product you are using).
Then try registering again, this time using the license file contained in the zip file.
IMPORTANT NOTE: Make sure that you use the license file contained in the zip file as that will remain untouched.