But, you can try to contact blockchain wallet customer care about it. But, how about downloading the blockchain app and try to login through app. But, I will recommend you not to use blockchain wallet because it is a web wallet, it requires emails which supposed not to be. If you remember your seed phrase, you can try and import the seed phrase on another wallet other than blockchain. You can try electrum wallet if it is only bitcoin that you have on the wallet, but if you have other coins, you can try trust wallet. By importing the private key on trust wallet, you should be able to recover your funds.

Try it in incognito/a different browser.

You could try removing cache on that browser you're using along with any add ons or plugins you might not be using. If it's happened multiple times with that site then it's probably something to do with your instance of it that's been cached or something.

Your browser could be having a problem. Just logged into my old Blockchain account without any problem or error using Chrome.

This is another one of the many disadvantages of web wallets that require you to log in. I advise you to back up your recovery phrase once you manage to log into your blockchain account and then use that 12 word phrase to import your account into a better software wallet like electrum. You have to suffer with the stupid login errors anymore