Background: Hello, I just inherited a site from a new client. Clients site was using version 5.7. They want their site updated to the latest version of Drupal. I read in the documentation that I should update to the most recent version of 5 (5.17) before upgrading to 6. So I began the updating procedures following the instructions step by step in the Upgrade.txt document.
Here's what I did:
1. Backed up all the files
2. took the site off-line
3. disabled the contributed modules. Clicked on "Save Configuration" and got my first fatal error. I had not yet switched to a core theme. I then removed my custom theme from the server via FTP. Luckily, the error went away and I was then able to switch to a core theme.
I continued with the upgrade.
4. Removed all the old files.
5. Uploaded the new Drupal files.
6. Replaced the "file" and "sites" directories with the backup ones.
7. re-installed the contributed modules.
8. Ran update.php
9. Turned all my modules back on.
Everything seemed to work.
All my data is being pulled from the database. I went to Logs/Available Updates/List and saw that the newer version (5.17) had in-fact been installed.
I then uploaded my custom theme and activated it. This is when everything went south.