We are all very familiar with the White Screen of Death in the Drupal world, AKA WSOD. One very common cause is a lack of memory for PHP - yet another is having errors turned off.

In development mode, you should probably make sure you are showing PHP errors on the screen, if this is an option. This is the kind of thing you can edit in your site-specific settings.php file, by using:

One of my sites had a funny error complaining about an "unsupported form of compression" shortly after installing a new module. The browser would return a white screen of death with an error message (Safari and Firefox).

Content Encoding Error
The page you are trying to view cannot be shown because it uses an invalid or unsupported form of compression.