Error 500 with KCFinder in CKEditor

Question

I get an error 500 when trying to upload an image to server in CKEditor (for example when using print/merge document action), when the KCFinder new window opens. The URL called is :

https://subdomain.mysite.com/sites/all/modules/civicrm/packages/kcfinder/browse.php?cms=civicrm&type=images&CKEditor=html_message&CKEditorFuncNum=0&langCode=fr

I thought about a https related problem, but this URL :

https://subdomain.mysite.com/sites/all/modules/civicrm/packages/kcfinder/

...is working fine and opens the KCFinder file browser.

Does anyone encountered this problem ? I can't reproduce it on demo site, I am running CiviCRM 4.7.10 with Drupal 7.50. I don't have anything in Apache logs.

I suspect a file / folder permissions issue too, does anyone have an idea on what is going on ?

Thank you

EDIT

I was able to open the file browser using this URL :

https://subdomain.mysite.com/sites/all/modules/civicrm/packages/kcfinder/browse.php??cms=civicrm&type=images&CKEditor=html_message&CKEditorFuncNum=95&langCode=fr (note the "??" just after "browse.php")

...but

https://subdomain.mysite.com/sites/all/modules/civicrm/packages/kcfinder/browse.php?cms=civicrm&type=images&CKEditor=html_message&CKEditorFuncNum=95&langCode=fr (only one "?" after "browse.php") still gives me an error 500.

very confusing...

Answer 1

My mistake, I left a hack in civicrm.settings.php (and forgot it, it was months ago) which led to this weird behavior. Reverting the hack solves the problem :

// can't remember why I did this 18 months ago, but this is obviously a bad idea...
//require_once './sites/all/modules/civicrm/CRM/Core/ClassLoader.php';
require_once 'CRM/Core/ClassLoader.php';

Many thanks to XDebug, and lesson learned (again :) about hacking CiviCRM code...