904 error - Crystal

I think you need to prefix the field identifier with the database schema. So instead of 

Select Value from prin1app.comm_Method Where
Company_ID ="CUST_STMT_ACCT_REP"."COMPANY" AND 
Party_type = 'Company' AND
Method_ID = 'Phone' AND
Method_Default = 'TRUE'

It would be :

Select Value from ifsapp.prin1app.comm_Method Where
Company_ID ="IFSAPP.CUST_STMT_ACCT_REP"."COMPANY" AND 
Party_type = 'Company' AND
Method_ID = 'Phone' AND
Method_Default = 'TRUE'

Thanks for the reply but still exactly the same.

Our applications owner has been changed from IFSAPP to PRIN1APP

Looking at the company field in the view you are joining, the field length may be around 2000 for the field company. If this is the case I am sure expressions are limited to specific maximum field length, so this might be the issue.