Cannot create references to/from string offsets nor overloaded objects

I'm getting the following runtime error in my PHP's error_log:

[Thu Jul 31 20:54:59 2014] [error] [client 98.176.242.59] PHP Fatal error: Cannot create references to/from string offsets nor overloaded objects in /var/www/drupal-7.27/includes/common.inc on line 6606, referer: http://myserver/mypath/summary?field_log_time_value%5Bvalue%5D%5Byear%5D...

and that URL results in a blank (white) screen.

I searched for this PHP error and saw a posting where someone said they upgraded their PHP and it fixed their problem. So I upgraded from 5.3.3 to 5.5.14 but the error and problem persist.

Please help!

(Note, I tried to search for the above title in the 7.27 core issues but got a blank page instead so please excuse this posting if it is duplicate or answered elsewhere. If it is answered elsewhere, I would appreciate a link to that page, thanks!)