BICS connection / Bex Browser

Hi

In CMC, when i create an OLAP connection with pre-defined  authentication i couldn't see the BEx Browser or Queries when use WebI Browser

I have this massage :

com.businessobjects.sdk.core.server.CommunicationException$UnexpectedServerException: [[error.openSapBwBrowsingSessionFailed] 0] <<?xml version="1.0" encoding="UTF-8" standalone="yes"?><ConnectionString>

Could you please help.