Login spontaneously stopped working

Can you describe exactly what happens from when you go to /wp-login.php ?
Have you tried these: https://faq.wordpress.net/view.php?p=68
Have you cleared cookies / cache ?

I cleared the cookies and cache on both browsers early on in the game and have cleared them several times since. This last time I ran a cache cleaner program (in Zone Alarm Pro), too.
I had not seen the other suggestions, but I just went through each of those and after I got to number 6 I saw a slight improvement. Before what I was getting was just returned to the login page no matter what I put in, even if it was completely bogus. After doing sexygirlgeek’s fix I at least get “error wrong login or password” if I put in the wrong password. But I still don’t get past the login screen when I put in the right password – it just sends me right back to login with the username and password blank again.
I’m running on Windows XP SP2 with Firefox 1.0PR and Internet Explorer 6.002.something on the client side. The error occurs in both browsers.
On the server side, Word Press versions 1.0.1 and 1.20 are both doing the same thing. Linux Kernel version 2.6.8.1,
Apache version 1.3.31 (Unix), PHP version 4.3.8,
MySQL version 4.0.20-standard.

Okay, one other thing I noticed that I think is different – there are these “%2F” s in the middle of things. AFter I log in it’s trying to send me to wp-admin/post.php but instead is sending me to %2Fwp-admin%2Fpost.php. Any idea what would cause that?
wp-login.php?redirect_to=%2Fnews%2Fwp-admin%2Fpost.php

I don’t know if this will be any help and I realise that you have tackled the cookie/cache possibility, but I have just spent a very frustrating afternoon with the same problem on my localhost server; for no apparent reason I suddenly couldn’t log in to admin, nothing I could do was making any difference I adjusted the cookie handling in IE, Firefox just refused the connection! I read the post on the general problem, nothing, I even did a secondary new install of completly fresh files and exactly the same problem the db was fine so I focused on the fact that I was getting a redirect with % variables in the pathname instead of a straight path when I noticed that I was blocking scripts in my Outpost firewall which in turn made me think to check the basic cookie permissions there, and of course I had been blocking cookies ( must have re-configured and forgotten) with cookies fully enabled log in was fine path name became wordpress/wp-admin/post.php again and Firefox desided it would accept connections? moral is I had assumed the problem to be more complicated than it was and had only focused on the browser for cookie and cache control and wonder if some of the many reported log in problems are due to overlooking the firewall end of things, it was just by chance that I looked at the login source and found that the javascript was being stripped out that I turned to the firewall.
Sorry rather rambling pos,t hope it may help someone?
Hugo.

i have this same problem, all in my localhost testing:
AFter I log in it’s trying to send me to wp-admin/post.php but instead is sending me to %2Fwp-admin%2Fpost.php. Any idea what would cause that?
wp-login.php?redirect_to=%2Fnews%2Fwp-admin%2Fpost.php
plase, help

@ the latest anon – is this new behaviour ? What have you tried to solve this ?
(And as an aside, this is a perfect example of why you should register. Three ‘anon’ postings in one topic makes it very confusing for someone reading and trying to help – and yes, I know Hugo signed his message – thanks ! – but registering is free, it takes all of about 1 minute and make life here so much easier. – Please register ?)

That did it. I hadn’t made any changes, but am using Zone Alarm Pro. They must have made an automatic update that changed something. I added my own sites to the site list under privacy and allowed all cookies and it’s working now. Thanks for the help.
re: registration. I thought I was logged in, so I didn’t realize I was anonymous. Sorry.
Tom Hanna
https://www.tom-hanna.net

Apologies, point taken podz, would have started to iritate me as well, just being lazy!
To re-iterate, my problem stemed from blocking cookies outright resulting in the variables in the path name in place of the proper directory path slashes the last anon post sounds like it may be the same thing but I’m sure the developers would know better whether that resulting type of error could be caused by more than one event?
the large post on the subject supprised and confused me as there seemed to no common denomenator to the problem and was being talked about as a mystery bug; rather a serious one if it is and having realised that in my instance the solution was actualy staring me in the face but I chose to look for more obtuse reasons the more frustrated I became. I wondered if in some cases the problem was being overlooked in the same way, although I’m sure the majority of users wouldn’t miss something so obvious ( my level of layered security is such that I forget where actions are taking place- dam my paranoia and the cretins that force me to it)
Hugo.

Just seen Tom’s post, glad to here that it was indeed the problem and is sorted, as it is quite disconcerting. Not a lot you can do when you can’t login!!
Hugo.

I’ll try and pull this information together for the wiki – thank you for posting ??