Junk {head} {styles} codes as output
Symptom:
When visiting your Drupal site for the first time you see what looks like code output, instead of the expected theme:
{head} {styles} {_BLOCK_.header.logo} {_BLOCK_.header.site_name} {secondary_links}
{primary_links}
{_BLOCK_.header.blocks} This chunk of code is followed by the standard welcome message.
Cause:
Changes made after 4.6.x was released in PHP 5.0.5+/5.1.1+ and the template engine XTemplate are incompatible.
The quickest solution is to go to http://www.example.com/?q=admin/themes and change the default theme to Chameleon or Marvin.
Before you can change the theme you'll need to be logged in. Either create the first account or login at http://www.example.com/?q=user.
Another solution is to switch to a PHPTemplate based theme. PHPTemplate is another theme engine, which will become the default in Drupal 4.7 anyway. You will need to download and install PHPTemplate before you can use themes that depend on it.
Make sure to disable all XTemplate themes to prevent visitors from using them. Drupal 4.6 comes with two XTemplate themes included: Bluemarine and Pushbutton. A PHPTemplate version of Bluemarine is available. Primary/Secondary links configured in the theme general settings will not carry over to PHPTemplate. You will need to re-configure any Primary/Secondary links in the PHPTemplate configuration of the theme.

{_BLOCK_.header.title} You are not authorized to access this pag
I've tried to login and change the theme, but I still get an un-theme'd page that says this:
{_BLOCK_.header.title} You are not authorized to access this page.
I reset the password for user 1 like so:
UPDATE `users` SET pass = MD5('newpass') WHERE uid=1;
and logged in with admin : newpass
This is where I get the message :
{_BLOCK_.header.title} You are not authorized to access this page.
Background info: the site was running fine with a customised skin, but I believe the administrators upgraded the PHP version, and some time later I went to check the site.
Cheers.
Murray.