Let’s look at a few reasons this error might be occurring.
You can confirm your account number in your Personal Area under My Accounts; the number is listed with a MT5 or MT4 label along with a Real or Demo tag. Confirm that this account number and the one you used to log in are the same.
Ensure you use the correct Trading Password when you log in. If you have forgotten your password, you can change it in your Personal Area under My Accounts. Click on the cog icon to the right-hand side of the account and choose ‘Change Trading Password’ to create a new one. Use this new password and try to log in again.
Check which server your account uses in your Personal Area under My Accounts. Click on the cog icon to the right-hand side of the account and it will list which server it uses (Exness-MT4Trial2 or mt4trial2.exness.com:443 are examples of what that might look like). Next time you try to log in, confirm that your server is correct.