PHP Fatal error: Can't use function return value in write context

Hi

I clicked the "Modifications" button on the advagg admin page and the page is empty.

In my mod-security log file; i saw this as the possible reason. Below is edited a bit to remove cookies and some names and paths.

--ea066112-A--
[17/Mar/2015:16:06:51 +0100] VQhDCH8AAAEAADtVDCUAAAAK
--ea066112-B--
GET /admin/config/development/performance/advagg/mod HTTP/1.1
Host: www.example.com
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:36.0) Gecko/20100101 Firefox/36.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: https://www.example.com/admin/config/development/performance/advagg/js-c...
Connection: keep-alive
If-Modified-Since: Tue, 17 Mar 2015 15:06:24 GMT
If-None-Match: "1426604784"

--ea066112-F--
HTTP/1.1 500 Internal Server Error
Expires: Sun, 19 Nov 1978 05:00:00 GMT
Last-Modified:
Cache-Control: no-cache, must-revalidate, post-check=0, pre-check=0
ETag: "1426604808"
Content-Length: 0
Connection: close
Content-Type: text/html

--ea066112-H--
Apache-Error: [file "/build/php5-tuWdu3/php5-5.4.36/sapi/apache2handler/sapi_apache2.c"] [line 325] [level 3] PHP Fatal error: Can't use function return value in write context in /home/webuser/public_html/example.com/sites/all/modules/advagg/advagg_mod/advagg_mod.admin.inc on line 119, referer: https://www.example.com/admin/config/development/performance/advagg/js-c...
Apache-Handler: application/x-httpd-php
Stopwatch: 1426604808501373 3260701 (- - -)
Stopwatch2: 1426604808501373 3260701; combined=33031, p1=1717, p2=31301, p3=0, p4=0, p5=12, sr=87, sw=1, l=0, gc=0
Producer: ModSecurity for Apache/2.6.6 (http://www.modsecurity.org/); OWASP_CRS/2.2.5.
Server: Apache

--ea066112-Z--