Error during proxy processing in SOAP to Proxy case

Hello Folks,

We have SOAP to Proxy Async scenario it is working fine in production these days frequently messgaes are failing with the below error when i see in Moni.

Error during proxy processing An exception with the type CX_SY_FILE_AUTHORITY occured ,but was neither handled locally nor declared in RAISING clause NO Authorization for accessing file '/interface/cidintlog_2013417_00125.txt;

When we repocess the failed messages they are going through .Any ideas why we face this issues is the error really related integartion or abap proxy ?

Regards

Praveen Reddy