I bought a new PC and want to transfer my Electrum credentials to the newly installed Electrum on my new PC.

I saved the 12 words and input it correctly but the field for NEXT is still disable and can't be clicked meaning something is wrong. How can I regain my backup? I need all my addresses listed on my old Electrum and want to transfer it to new one. There are lots so importing address one by one can be time consuming.

I still have my Electrum file on the old PC and not uninstalling it yet. Thanks.