Steps to reproduce:

1. Have 300 empty hosts. 
2. Go to User Settings->Profile and set 
   Rows per page = 300
3. Go to Configuration -> Hosts
4. Select  all 300 hosts and click Mass update
5. Try to link "Linux by Zabbix agent" to all these hosts
6. Get error:
   
   The item and host name in the error will be randomly different:
   
   

This works fine in 6.0 and 6.4.