strawman49
I am running dokuwiki Release 2016-06-26a "Elenor of Tsort" and using php 7.1. After updating or installing a new plugin the display was messed up. I tracked down some old articles about what to do if the template doesn't display correctly. Trying to display the css file with /lib/exe/css.php?purge=true showed me this error:
<br />
<b>Fatal error</b>: Uncaught Error: [] operator not supported for strings in /home/httpd/dokuwiki/lib/exe/css.php:169
Stack trace:
#0 /home/httpd/dokuwiki/lib/exe/css.php(140): css_parseless('@ini_text: #333...')
#1 /home/httpd/dokuwiki/lib/exe/css.php(18): css_out()
#2 {main}
thrown in <b>/home/httpd/dokuwiki/lib/exe/css.php</b> on line <b>169</b><br />
and this is line 169: $less->importDir[] = DOKU_INC;
After a lot of reading and not understanding about arrays declared as strings or whatever, I tracked it down to inc/lessc.inc.php
I crossed my fingers and made the following change:
54 // public $importDir = '';
55 public $importDir = array();
Restarted the server and tried to update the Gallery plugin, it worked just fine.