I've just made a new test environment with a new Debian server and fresh install into a VM and the problem is still here !
This is not a problem with an uprade error.
OS Name : Linux x86_64
Version : 3.16.0-4-amd64
RAM installed : 986 MB
Free RAM : 673 MB
CPU : Intel(R) Core(TM) i5-7440HQ CPU @ 2.80GHz
Distribution : Debian GNU/Linux 8 (jessie)
PHP Version : 5.6.30
Web Server : Apache/2.4.10 (Debian)
Database Server : (Debian) version 5.5.55-0+deb8u1
Version OCSReports: 2.3.1
The problem is present too with OCS 2.2.1 on a Debian server up to date after a fresh install...
EDIT 2 :
...testing on VMs Debian 8.6 and 8.7 and OCS 2.2 = the error is here too...
I think, maybe, there is a compatibility problem with a newer version of a dependencies, perl, mysql or apache...
EDIT 3 :
Same problem on Debian 8.6 and OCS 2.1.2...
# mysql -V = mysql Ver 14.14 Distrib 5.5.55, for debian-linux-gnu (x86_64) using readline 6.3
# php --version = PHP 5.6.30-0+deb8u1 (cli) (built: Feb 8 2017 08:50:21)
# apachectl -V = Server version: Apache/2.4.10 (Debian)