Error 100, 101, or 5008 indicates a typo.
That's why the license can't be found on the server. The typo you're making is either when you're typing the license ID or the password. If it is an EQ7 Upgrade, the typo you're making could be in the EQ6 license ID or password, or the EQ7 license ID or password.
Make sure you're typing in the password that is listed on the sticker in the back of the EQ7 book... not your own password.
It may help to type your password into a text document and copy and paste it from there so you can see the characters being typed.
If you continue to have problems, email firstname.lastname@example.org
with your license ID and password for EQ7 (include them for EQ6 too if it is an EQ7 Upgrade). We can cross-check them against what the database is expecting.