In the Administration Center → Search → Search Method I had the "Search Method" selected to be a Custom Index but after switching to PHP 7.1, I am no longer able to get the search to work. When a search is done it yields a blank page with Custom Index as the selected search method. In my case no errors are being generated as have been mentioned in these two recent support threads...
[2.0.14] PHP7.0 and search with custom index error
https://www.simplemachines.org/community/index.php?topic=556505.0
2.0.14 search function http error 500
https://www.simplemachines.org/community/index.php?topic=553979.0
If I select the option "No Index" in the search method settings the search works fine.
In an attempt to fix the issue I tried deleting the existing Custom Index and after rebuilding it the same issue is present... any search will result in a blank page with no server errors or SMF errors.
The particulars of my forum is as follows...
Version Information:
Forum version: SMF 2.0.14 (more detailed)
Current SMF version: SMF 2.0.14
GD version: bundled (2.1.0 compatible)
MySQL version: 5.6.36-cll-lve
PHP: 7.1.7
Server version: Apache
I was wondering if maybe a PHP module was not installed by my host so I talked with them about this and comparing PHP 5.4 which I came from, to PHP 7.1 we saw some consistencies of modules and some new PHP modules that were introduced. Is there a PHP module dependency that might be the root cause of this?
It's a bug.
Fixed in 2.0.16