Your Problem Could Be “Disable WordPress Widgets”

What it took for me to get in to my Dashboard was through a link in an email asking me to approve a comment. That somehow by-passed the login blank screen. From there, I went through the list of all my plugins and found that when I had updated to 2.6 it had activated a plugin that I had previously not been using: “Disable WordPress Widgets” https://schulte.mn/2007/05/04/disable-wordpress-widgets/ is no longer necessary, and if you do happen to have it checked and activated, then that may be the reason your widgets might not be showing up on your blog. So, if you have this plugin in your list, you can probably delete it.