In many cases, the problem is that you are entering the wrong MSID. Sometimes users mistake the letter O for the number zero (0).
If password entry fails three times, you will be locked out and will therefore receive the error message (authentication method blocked).
(click to expand)
In addition, the initial MSID entry counts as the first attempt. The "Create a password" counts as the second try.
So, it will not take long to get the count of 3 failed attempts before the you are locked out.
Thus, you really have only 2 attempts to get the MSID correct.
After entering the wrong 25-character ID code, you will get the following pop-up windows at first and second attempt.
On third attempt and after that, you will get the following messages.
At this point you need to disconnect the drive, then reconnect the drive to start over. Make sure to try replacing O with 0 and 0 with O in your attempts.