Updates failing to Import from Catalog.

I  facing an issue with importing update from catalog to the WSUS server.

Here is the error message

FATAL: Invoke() failed for method ImportUpdateFromCatalogSite with 0x80020009.
FATAL: Exception message:"The request failed with HTTP status 404: Not Found.". Exception Source:"Microsoft.UpdateServices.BaseApi". scode=0x80131509.
CatalogWebControl::ImportToWsusCore: InvokeWsusImport() failed with 0x80131509.

I have only one stand alone WSUS server serving 700 clients. Not sure what is causing the issue. 

Any pointers?