Received empty inbound container file for user DEMO

When we synchronize on MI client 2.5 Sp 12 we receive the following message

"Received empty inbound container file for user DEMO "

In trace file i get somme errors like :

E [Unknown ] java.lang.NullPointerException: no message available

java.lang.NullPointerException

at com.sap.mbs.mam.bo.impl.Mam095ManagerImpl.getMam095Item070s(Mam095ManagerImpl.java:710)

at com.sap.mbs.mam.cstm.impl.CstmCustomControllerImpl.getDeviceSettingsProfile(CstmCustomControllerImpl.java:251)

On the merep_log monitor the message text indicate this:

MEREP_502 database update failed

RAISE ACK_RECEIVED_BUT_DBUPDATE_FAIL 0000000091 1 CD66091C5989AA4A8AEFC3CAF3A44B51

Can anyone help me

Gratefull

Fethi