File this one under just-in-case-your-run-into-this category. I have been running WordPress from the svn repository for a while now and was just recently burned. I found that I could no longer enable or disable plugins. I was just given a message that the action failed, with no reason whatsoever.

If you see this, the quick solution is to check if you have a wp-content/plugins/plugins.php file. For some reason, I had this lying around; it should instead be using the wp-admin/plugins.php. Removing this file gives you the new fancy plugin page.

The strange thing about this is I had to dig around in the code to find what the real file should have been. Why it was loading that incorrect file, I have no idea. No one else seemed to report this problem, so I figured I’d mention it here so perhaps the Google Sitemap would help others find this solution.

Update: As I posted that, I found out the hard way that ask.com is no longer working with the Google Sitemap. If you are using this plugin, disable this in the Settings page.