Could be your permalink structure needs updating.
See: Settings_Permalinks_SubPanel
Same error for me. All pages will give 404 error.
Changing to default theme will not help.
My current permalink structure is Custom structure /index.php/%postname%/ and it has been working from version 1.56.
Changing permalink structure to default will solve 404-problem but this is not a solution. Same thing happens in multiple blogs I maintain.
I have the same error:
I made a new installation of wp 2.5 (on localhost).
It works with page-id. But I have set the customize permalink structure to “/index.php/%postname%/” – just like I have done on the wp 2.3 installation (here it works perfectly).
With this setting all PAGEs give a 404 error. Not even new posts are found.
Please help? Thank you in advance.
Same here, I got this error. I just upgrade last night and check all my pages (i.e about me, contact) it all give me a 404 error.
But I don’t have problem with my post, archive, and even categories, it’s all works fine.
I try to deactivate all my plugins and even change my theme, but still the same problem. Please Help!!!!
My permalink is “/index.php/%category%/%postname%?/ (pathinfo)
Help!!!!
Hi, I have the same problem. It only happens after the blog goes blank (I get an Install page like with a new installation) at random times (but too often). It goes back online after I look in the MySQL databases, and that might last 1 second to a couple of hours.
I loose all permalink structures each time, and I have to update them in order to keep being able to navigate to single posts…
I tried everything already: I THINK THIS IS A VERY IMPORTANT ISSUE. I HAVE SEEN IT IN MANY THREADS ALL WEEK. WILL ANY MODERATOR SAY SOMETHING ABOUT IT?
http://wordpress.org/support/topic/167628
I think it might have someting to do with the number of database queries:
http://wordpress.org/support/topic/168510?replies=1