Resolution:
This would occur if there is more than one schema which defines the same element belonging to the same namespace AND the process or activity does not use the correct schema anywhere in this process.

Engine will end up searching the namespace cache which will have duplicate element definitions belonging to the same namespace.

This is a basic schema problem and it should be solved by removing one of the schemas in the BW project.

If for some reason there is a requirement for both of these schemas to exist in the BW project the following workaround can be used.

In the process definition, add a dummy "Parse-XML" activity and choose any element from the correct schema  and save the process.
This will add the following lines to the ".process file"

example:-
.....
    &ltxsd:import namespace="USBANK.SSM.MW.WSADMCreateCustomerPersistReq" schemaLocation="/SharedResources/SchemaDefinitions/WorkflowServiceAdapter/CreateCustomer/WSADMCreateCustomerPersistReq.xsd"/>
.......
Once you made sure the ".process" file has above lines delete the dummy activity from the process.
Run the process now and it will work fine.

When would BW report the following error ""Resolution error: Error Component defined in at least two fragments.. "Keywords :- Namespace conflict, resolution error