When I write them into Electrum during the restore from seed box, the Next button is disabled.
Breadwallet uses BIP 39, but Electrum no longer does. However, Electrum does have a compatibility option for BIP 39 seeds. Just click the "Options" button and check the box labeled "BIP 39 Seed".
Breadwallet uses BIP39, which Electrum's seeds are is not compatible with.
(There are some people online saying it's possible to make it work, but I can't figure it out.)
As an alternative, MultiBit is compatible with BIP39.
Here's a spreadsheet, written by Christopher Gurnee, showing a list of wallets, and whether those wallets are compatible with BIP39.