My b2evolution Version: 1.9.x
In my new install it never showed me my Admin password (that I'm aware of) but it does let me into the Admin tools and says I am logged in as Admin.
When I go to the Users tab, where I presume I would change the Admin password to something I know, that tab is blank. All other tabs seem to be fully functional.
Any ideas?
-B-
Did you do a fresh new install or an update. If it was an update, the settings for the admin, including password are not changed.
Nevertheless if I get the description of your problem right, there is something else going on. Try uploading all the files again. There might be missing a (few) file(s). If the problem persists, don't hesitate to report it at this site.
Good luck.