Permission denied in class-wp-theme.php for page editor?

I’m getting the following error message on the editor screen for pages in the “Page Attributes” box between Parent and Template:

file_get_contents(/home/schuminwebcms/schuminweb.com/wp-content/themes/modern-blue-2/images/en.php) [function.file-get-contents]: failed to open stream: Permission denied in /home/schuminwebcms/schuminweb.com/wp-includes/class-wp-theme.php on line 948

Then when I save pages, the edit goes through, but rather than going back to the editor screen, I get the following error message:

Warning: file_get_contents(/home/schuminwebcms/schuminweb.com/wp-content/themes/modern-blue-2/images/en.php) [function.file-get-contents]: failed to open stream: Permission denied in /home/schuminwebcms/schuminweb.com/wp-includes/class-wp-theme.php on line 948

Warning: Cannot modify header information - headers already sent by (output started at /home/schuminwebcms/schuminweb.com/wp-includes/class-wp-theme.php:948) in /home/schuminwebcms/schuminweb.com/wp-admin/post.php on line 233

Warning: Cannot modify header information - headers already sent by (output started at /home/schuminwebcms/schuminweb.com/wp-includes/class-wp-theme.php:948) in /home/schuminwebcms/schuminweb.com/wp-includes/pluggable.php on line 896

This problem occurs only for pages. Regular posts and my various custom post types do not have this problem.

In trying to fix it, I have replaced the wp-admin and wp-includes folders on the server with ones from a fresh install of WordPress, and have gone through and deactivated various plugins to determine if a plugin was causing the problem, to no avail.

Any ideas?