Linux/UNIX sets limit for the number of file handles and open files. You can use ulimit command to increase it.

Solution:

• For 7.6 or later version
  Open: <your chat installation directory>\server\fcserver
  Find: if [ -z $FCSERVER_HOME ] read_db_entry()
  Add before: ulimit -n 65535

Then start the server with root access.

• For the version earlier than 7.6
  Open: <your chat installation directory>\server\fcserver.sh
  Find: if [ -z $FCSERVER_HOME ]
  Add before: ulimit -n 65535

Then start the server with root access.