After an update from modx revolution 2.5.7 to 2.6.3, i was unable to connect to the manager.
I've looked for solution for a long time an finally found this guide (
http://bobsguides.com/blog.html/2014/01/02/locked-out-getting-back-into-the-modx-manager/) but the solution wasn't complete
If you've tried everything including "the ugly method" from Bob's Guide, check if your table modx_users in the corrupt site have the same numbers of columns than the one in your new installation.
For me, after the update, the column "createdon" was missing. And that prevent me from log in to the manager.
Good luck
