Billing not Possible- Overall Status Blocked

Hello All,

I have a problem while creation of the Billing document based on Order. Our Scenario is of Service Billing i.e. Contract->Order--> Billing.

Problem: While creating Billing -Error Log is created stating " Document xxxxxxxx blocked for billing'

When I checked the Sales Order for any blocks, the Header Status shows Overall blkd status as Blocked.

The Sales document is also released for Credit., the Customer has no blocks set.

Can you help me in tracing out the reason.

Regards,

Karthik.