Can you please explain your question in detail. what are the ERRORS your are facing in connecting hash file to transformer.

Please be proper in your question.

If Hash file output is connected to transformer stage the hash file will consider as the Lookup file if there is no primary link to the same Transformer stage if there is no primary link then this will treat as primary link itself. you can do SCD in server job by using Lookup functionality. This will not return any error code.