There are confirmed reports in the Google Webmaster Help forums that Google Webmaster Tools is not loading in all browsers.

Pierre Far of Google confirmed the issues saying:

Thanks for the report. We know of an issue affecting how some browsers fail to display the new home page. Just to be sure what you’re experiencing is not a new issue, can you please take a screenshot of how it’s breaking for you? It would also help if you mention which version of Windows you’re running.

Here is a picture of how the home page loads in Internet Explorer 9 using Windows 7:

There is not estimate time for a fix for this bug. This isn’t being widely reported or complained about either.

Forum discussion at Google Webmaster Help.

Article source: http://www.seroundtable.com/google-webmaster-tools-browser-14173.html