Updating Drupal: Things to Check
There is a rumour going around that Drupal's 6.19 update makes a site fail. I made the update on several Drupal sites just fine, but I was getting the following error after updating the last 6.17 site:
It worked fine with my other sites, including multisite setups sharing one database through the Domain Access module. First check are the paths to your modules and compare them against the system table in the DB. Then check for duplicate core components that may confuse Drupal. Another good tip is to re-upload the core components via FTP, just to be sure all of the files made it to their destination.
When all of these didn't work, I looked at the Filter module itself. In my case, it was Filezilla causing the problem. For some reason, when I uploaded the core and module components the file modules/filter/filter.module reported a 0 filesize.
I tried to re-upload the file in question, and it still gave me grief. Finally, I deleted the file on the remote server and uploaded a 4th time with success. After that, update.php ran fine.
