index fails on EV 10

hi,

I have new installed EV 10 environment.

After configuration 1 user enabled on system.archiving is working no problem.

But 1 day later i seen that this user index is failed,i tried index rebuild and verify but it still shows index failed in archive properties.

event log say that;

 

Log Name:      Symantec Enterprise Vault

Source:        Enterprise Vault

Date:          11/17/2011 2:56:30 PM

Event ID:      41329

Task Category: (136)

Level:         Error

Keywords:      Classic

User:          N/A

Computer:      company.local

Description:

Index volume is marked as failed.

 

Archive Name: evtest

Index Volume ID: 1855154C5926C71469433519AB360F57F1110000archive_1

Reason: IndexingEngineError

Error Type: CriticalError

 

Description: Request rejected. Check requestFiltering settings in web.config file.