Can't access my bitcoin wallet

So, I tried adding my private key to an Electrum wallet, but it shows a balance of 0. However, when I put my Bitcoin addresses into a wallet, my actual balance shows up, but it’s just read-only. How do I actually get access to my bitcoins?

Is this what you're looking for?

You need to identify the type of address format that holds your bitcoin. You didn’t prephend you private key before importing it and it generated a different address and that’s why it’s empty. Follow this guide to import it properly https://bitcoinelectrum.com/importing-your-private-keys-into-electrum/ The reason why it was a watch only wallet is because a wallet imported by an address is a watch only wallet because you can’t sign a transaction from that wallet only if you import a seed phrase or private key into wallet that you can spend from it

Apart from LoyceV's answer which will probably solve your issue, do you want to share with us the address type? Is it P2PKH (starts with 1), is it P2SH (starts with 3) or is it P2WPKH (starts with bc1q)? Also, how did you generate your private key? It is significant to know, because perhaps, if the address is P2PKH, it could be uncompressed.

This question is not necessary because LoyceV has already answered the question. If you do not add any thing to the front but you just paste the private key, that is bitcoin address that starts from 1 which was what the OP did. While LoyceV has also given him what to do for addresses that from 3 and bc1.

Ok. But an uncompressed vs compressed address may be the issue with OP here. Apart from that, it will also help to know how OP generated the wallet, so my question still stands:

I do not think that is what that happened but you are not wrong. Let me say I have a private key which starts with 5, that is not compressed. It is not possible to become compressed unless I use a tool for it. People will prefer to just write the private key down in the format they generated it. If he follow what LoyceV put up there, he will see his bitcoin.

Now I understood why they don´t work, I exported them from a 2FA Wallet, because I don´t have the 2nd authentification anymore. I also have the seed of the wallet, but if I try to make a new normal wallet with the existing seed, the balance is 0. But I can´t make a new 2FA wallet with the seed, bacuause it is a 'standart' seed. Does anyone know, how I can get access to the wallet, without the 2nd authentification?

If you have set up 2FA, you shouldn't be able to do what you want. You shouldn't be able to access the wallet without the 2FA. Otherwise, why set the 2FA in the first place if it's unnecessary? You still haven't answered my question though: Can you elaborate? With as much detail as you can. Of course be careful not to share sensitive data.

I can access the wallet without the 2FA, but I can´t make any transactions. I exportet the private keys from the electrum wallet, but with them I can´t get access to the wallet, bacause they are p2wsh-keys, not p2wkh-keys.

Is this the "default" Electrum 2FA? If so:

Yes, but if I restore it as a normal wallet, the balance is 0. If I try to restore it like descriped here https://electrum.readthedocs.io/en/latest/2fa.html I get the error, that it is a 'standart'-seed. Does anybody know, if they changed something regarding the 2FA seed at electrum? Because I am quite sure, that this is the right seed

Electrum 2FA wallet is a 2 of 3 multi-signature wallet and you can't generate any of its addresses with using a single private key. Electrum uses different versions numbers for 2FA and standard seeds and it's not possible that a 2FA seed can turns into a standard seed. You are probably entering a wrong seed phrase.

If you still have the seed I have a suggestion this should work since this is what I did when I recovered my old 2FA wallet with my seed backup. I'm talking about the tool from trustedcoin it was created due to fork coins but it also works to gain access to your old 2FA wallet it generates an Electrum-compatible 2-of-3 multi-signature wallet file that you can import to Electrum without a 2FA. Here's the tool https://trustedcoin.com/static/recover/standalone.html Please download the page, run it offline for safety purposes, and transfer BTC immediately to a new wallet.

As far as I know, Electrum updates are usually backwards compatible. So, it sounds like you don't have access to the 2FA-part, and you don't have access to the wallet's seed. How did you even get this wallet?