CALL_FUNCTION_REMOTE_ERROR - Logon not possible (error in license check)

Hello,

We are getting the following dump in production system -SAP ECC 6.0.

The wp s are getting terminated automatically as shown in dev_disp file.

.........................................................

Sun Aug 10 12:15:38 2014

DpHdlDeadWp: W2 (pid=25722) terminated automatically

Sun Aug 10 12:16:46 2014

DpHdlDeadWp: W34 (pid=8081) terminated automatically

Sun Aug 10 12:23:45 2014

DpHdlDeadWp: W28 (pid=25734) terminated automatically

...........................................................

The dev_ms shows the following :

[Thr 139866179913568] Thu Aug  7 00:25:35 2014

[Thr 139866179913568] *** ERROR => MsSCheckConnections: no response from client C11 (161.134.204.144) after 300 secs received [msxxserv_mt. 4136]

[Thr 139866179913568] *** ERROR => MsSCheckConnections: disconnect now [161.134.204.144] [msxxserv_mt. 4140]

[Thr 139866179913568] Thu Aug  7 10:20:56 2014

[Thr 139866179913568] *** ERROR => MsSCheckConnections: no response from client C22 (144.145.30.11) after 300 secs received [msxxserv_mt. 4136]

[Thr 139866179913568] *** ERROR => MsSCheckConnections: disconnect now [144.145.30.11] [msxxserv_mt. 4140]

[Thr 139866179913568] Fri Aug  8 09:35:00 2014

[Thr 139866179913568] *** ERROR => MsSCheckConnections: no response from client C20 (139.24.138.145) after 300 secs received [msxxserv_mt. 4136]

[Thr 139866179913568] *** ERROR => MsSCheckConnections: disconnect now [139.24.138.145] [msxxserv_mt. 4140]

[Thr 139866179913568] Fri Aug  8 09:35:40 2014

[Thr 139866179913568] *** ERROR => MsSCheckConnections: no response from client C12 (139.24.138.145) after 300 secs received [msxxserv_mt. 4136]

[Thr 139866179913568] *** ERROR => MsSCheckConnections: disconnect now [139.24.138.145] [msxxserv_mt. 4140]

Last log on August 8.

What could be the reason?There are no licenses expiring..

Thanks and regards,

uday.