Support

Well, you should read the fine manual and no, this is not a bad attempt at a joke at your expense. Please let me explain the logic behind this message which is there to prevent you from doing something potentiall harmful to your site. You did not understand two very basic things:

1. You are not changing the Super Administrator password, you are changing its numeric ID. This has some very important repercussions to your site.
2. When you try to change the Super Administrator numeric ID a new user account is created and the old one deactivated, as per the documentation. You are asked which username you believe will be used by the new user account. The executive summary of this information is printed in a box at the top of the page, above the button you use to run this feature. You replied incorrectly, which means that you do not understand what you are about to do. Admin Tools stopped you from doing something you don't understand, it's potentially dangerous and would land you in the unfortunate situation of having done something major on your site without understanding it adequately to undo it.

Therefore you have to read the fine manual: https://www.akeebabackup.com/documentation/admin-tools/adminuser.html Read it carefully. Understand what you are about to do. Be very careful and aware of what you will be doing to your site. If it breaks you will need to be able to follow the steps under the "Undoing the changes made by Admin Tools" section in the documentation page I linked above. If you are still not sure what you are about to do or doubt your ability to follow the undo instructions should the need arise I strongly recommend not using this feature.