Are you referring to your MT5 account?
If yes, there are few possibilities to get this error, meanwhile please try the below steps - usually, it helps:
- We will request you to reset the password first. ( Reset instead of changing it)
- We need you to make sure you have keyed in the correct account number and server. Click here to make sure you have the correct details.
DMT5 Login Failed due to “Authentication Failed” - Server
- If you still encounter the same issue, we will need a screenshot of the Journal option .
- Once you have for the screenshot, please contact us via LiveChat and we will assist you.