@Abdussamad @HCP
it is the first time i use electrum on Jan 6, 2017, and I saved my seed, and never generate other wallet, so it is the only wallet i use with electrum
and it is the right address because it can displayed as 2FA when I input all 12 words.
so it the right address and only address, I cannot imagine which step is wrong, please help me.

But I have wallet.dat file and I can do transfer normally because I can get correct 2FA code.
And I have transfer all my bitcoins to another wallet, but About BCC, because I cannot restore my wallet without correct 2FA seed, so it is very sad for my, because I will lost my several hundred BCC, please give me some addvice , thanks.

I mean I have wallet.dat and 2FA code, it should be resonable to disable 2FA with 2FA code and wallet.dat