If you have come to update Magento and got the message “Magenta Connect – Access is locked. Please try again in a few minutes.” and you are prevented from logging in to process updates the chances are the Magento itself is blocking this.
Check using FTP if you have the following file?
Then look at the file contents and the chances are you have brute force number as an example:-
brute-force-bad-attempts-count = 1632
brute-force-diff-time-to-attempt = 97920
brute-force-attempts-count = 3
brute-force-last-bad-time = 1537569507
You need to change the files first two lines to:-
brute-force-bad-attempts-count = 0
brute-force-diff-time-to-attempt = 180
You can remove the other lines or changes the values to zero.
You can then update an old version of Magento and its core elements.