[xwiki-users] Display problem: gray background

Hi all. I'm using xwiki for some months and it was going very well. But today I've got the following problem: When I try to access any page, it loads and then it turns into a gray background right after the loading. I can, however, access the code by the browser. The last thing I did before this happen was change the layout of an app via App Within Minutes. I have not changed a single line in the source code. I have also tried to access with another browser and restarted the server, with no success. I think it's a problem with Javascript and how it displays the page, but I don't know very well Javascript to check where is the error. I'm using Tomcat 7 and Mysql 5.6. The Xwiki's version is 5.3, I think, but I can't check it for sure because I cant see it =P. Here's a print screen: http://imgur.com/PgL5uak Thank you very much.