Are you 100% sure you are typing the seed correctly? There is a checksum to detect typos. A single typo in the seed will prevent the "next" button from lighting up.

BTW, older versions of Electrum did not have the checksum, so if you type the seed wrong it will seem to work, but the addresses will be all wrong and you won't see your history/balances. That is why they added the checksum in newer versions.