If you upgrade to PHP5.6 must work.
Here is example of that problem.
http://sandbox.onlinephpfunctions.com/code/d50f416563c2b5cfa163f2f242f520ab54762a46
If you put below PHP5.6 will generate error. If you put PHP5.6 will work fine. Something is not running well on your server.
Please double check or call system administrator.