User blog comment:Rappy 4187/Technical Update: November 2, 2016/@comment-24473195-20161103171231

Really, either recent changes to the search page caused issues or these were always there and need to be tested using proper unit tests. Some examples of software defects, search for:


 * Space - "  "
 * Result: error 500 - http://dev.wikia.com/wiki/Special:Search?search=+


 * Plus "+"- http://dev.wikia.com/wiki/Special:Search?search=+
 * Result: error 500


 * Namespace - e.g.   "Project:", "Template:" - http://dev.wikia.com/wiki/Special:Search?search=template:
 * Result error 500

There may even be more issues. While the first two definitely wouldn't yield any useful data on a normal wiki, it may be possible to have such a page using escaped characters e.g. https://en.wikipedia.org/wiki/+.