Crystal Reports: Generating duplicate data of sub reports

Question

My root issue is opening the reports in the browser (crystal reports viewer) without getting prompted with parameters for the sub reports. Resolved this by linking the parameter from the main report to the sub report.

Next issue encountered was not being able to create or view the report with the error "Invalid group condition" Resolved this by removing the groups in the sub report.

Next issue was not being able to display the data in the sub report. Resolved this by replacing the fields in the sub report (these are database fields ) with formulas.

Right now, i already have a working report. In this report, i have amounts which i need to mask depending on the currency. When i added a custom style formatting on the amount field, my sub reports data were duplicated. This only happens on the generated file or on crystal reports viewer, but when i generated this on the designer it seems to be working fine.

Any ideas on how to resolve this issue?

Main Report Design:

Report Header: Header
Page Header:
Group Header #1: MAIN REPORT HEADER
Details: MAIN REPORT DETAILS
Group Footer #1:
Report Footer a: SUB REPORT
Report Footer b: Footer
Page Footer:

Sub Report Design:

Report Header a: Title
Report Header b:
Details: SUB REPORT DETAILS
Report Footer a:
Report Footer b:

Answer 1

Finally resolved the issue.

I suppressed the details in sub report everytime Field A <> Field B.

And also a correction to myself, grouping actually works on linked sub reports. Its such that the field you are using to group needs to be on the screen itself otherwise an error ("Invalid group condition") will be thrown.