Q: I was changing some PHP code in one of my blocks, saved it, and now my website won't display at all - how can I fix the problem?
A: This is a real pain, but to get around the problem you can update your drupal database directly to switch off the block, your website should then work again and you can fix the PHP error.

Sometimes if you save a block that contains a PHP error, your drupal website may no longer display at all, and you can't easily undo the error or switch off the block as you can't access the admin pages - very worrying stuff!

To get the site up again you need to switch off the offending block, this can be done by manually updating the drupal databse.

NB Before messing around with your database make sure to back-it-up first as it is very easy to make a mistake and do real damage to your website!!

To switch off the bad block, first Launch phpMyAdmin and browse the 'blocks' table, you should see a list of all your blocks. Have a look for the offending one, you should be able to spot it by its title or other distinguising attribute. Once you find it take a not of its 'bid', this is its unique identifier and is the first column of the 'blocks' table, let's call this offending_bid.

Now, from phpMyAdmin execute the follwoing SQL:

UPDATE blocks SET region='',status=0 WHERE bid=offending_bid

Remember to replace 'offending_bid' with the bid of your bad block.

This SQL, once executed, will switch off the block and your site should be operational again - now you can fix the block!!

To prevent this from happening again it's always a good idea to have your block only display on a test page when you're developing it. To do this, modify its settings so that in the 'Show block on specific pages: ' section the option 'Show on only the listed pages.' is selected and provide the path to the test page in the box below. Now if an error creeps in again it will only affect this page!

This happened to me (again) last night, and it's not a nice feeling at all, so I hope that this post helps someone in a similar fix!