The “invalid account” / “authorization failed” / “unauthorized” messages are related to you either entering your password incorrectly or choosing the wrong server.
Please be sure to select mt4.kot4x.com (KOT4X-Live) as the server when logging in to a real account.
For Demo Accounts, the selection should be KOT4X-Demo (demo.kot4x.com). If the server selection is not the issue, please try resetting your MetaTrader password. This can be done from the "My Accounts section. See screen shot below.
- Click "My Accounts"
- Click "View" on the account in question
- Click "Actions" tab in that account
- Click "Copy" the password and then click "Submit" on the system generated password