{{This post is a bit of a blast from the past, being somewhat historical. Well, I can’t change the publication date like I could in Drupal (I won’t go into the reasons I quit using Drupal just now) so it gets bumped up to 2017…}}

Since this keeps catching me out every time I haven’t had to update Drupal for a while, here’s the most common way that Drupal manages to “500 Internal Error” itself after an update:

.htaccess

One little hash can totally ruin my day (well, for about five minutes until I remember why exactly everything is broken…)

Find the line:

# RewriteBase /

and change it to read:

RewriteBase /

Job done. Simple, but incredibly annoying if not expected, as it doesn’t break the ‘main’ webpage… just every other page and link on the entire site.

NB: If you’re sensible and running a tight set of permissions on your .htaccess file, don’t forget to chmod it first so you can actually make changes, then chmod it back again when done; forgetting that last bit can be a Bad Thing™.