Customize Theme in Admin Broken

[Son_of_the_Raven]

I downloaded WordPress 4.1-beta2-30693 and when I go to Appearance > Customize in the admin section I get a 403 Forbidden Error. If I choose Customize under Appearance > Themes, all works as expected.

[MikeHansenMe]

I am unable to reproduce this. Are you using any plugins/themes besides the default?

[Son_of_the_Raven]

It is a clean install. The only plugin active is the WordPress Beta Plugin.

I looked at my raw logs and I found this line as a 500 error:

108.67.81.64 - - [02/Dec/2014:10:43:29 -0500] "GET /dev/wp-admin/customize.php?return=%2Fdev%2Fwp-admin%2Findex.php HTTP/1.1" 500 - "​http://www.domain.com/dev/wp-admin/index.php" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.71 Safari/537.36"

FWIW, it looks like it is trying to edit the admin page instead of the theme.

[ocean90]

Does it work in WordPress 4.0.1 on the same server? Can you please check your PHP error log? What happens when you access the Customizer via http://domain.com//dev/wp-admin/customize.php?return=%2Fdev%2Fwp-admin%2Findex.php directly? What happens when you click on the Appearance > Header/Background links?

[Son_of_the_Raven]

I will check it as soon as possible. I am working on another project that needs my full attention at the moment. I will set up a test tonight.

[Son_of_the_Raven]

Did a separate install of 4.0.1 and got the same error. I checked another site I've worked on too. I got the same error there.

[celloexpressions]

Most likely the issue here is something server-related that's avoided when the Customizer is loaded in an iframe. The other, bigger difference (besides the return param) between those two ways of loading the Customizer is that the customize-loader script is used to load the Customizer in an iframe over the admin on the themes screen (and the dashboard).

[afercia]

Was anyone able to reproduce this issue? If not, I'd kindly suggest to close this ticket.