A few questions:
Are you absolutely sure that you have entered exactly the correct password?
Do you have cookies enabled in your browser? If you don't have cookies, you will constantly need to confirm the browser.
Can you provide a picture of the error?
Error Decrypting Wallet. Please check your password is correct.
i allowed cookies now and tried again nothing changed.
i am sure about pass because of that mnemonic,i have taken photo of it , entered manually to site it shows your password so copy pasted but not worked.
just noticed my pass doesnt includes symbol ,if you create a new wallet now it demands a symbol in your pass otherwise not accept.
if this is a problem , it shows coding management is stupid.
That's not true, I just created a test wallet and entered a password without any symbols and it was accepted, the only thing required is that the password should be 10 Characters long. And I was able to access my account using the same password. What chrome version are you on? Clear all the cache, history and then use the link in your email to login, use the identifier which was given in your email (the one which contains long string of numbers & letters xxxx-xxxxxxxx-xxxxx-xxxx) and not the one you made yourself and I think you'll be able to get access to your account.
If you have a back up then just make a new wallet either on blockchain or use a desktop wallet like electrum and you can import the keys of addresses which contain the funds.