Here's the deal ...
The report uses a stored procedure which accepts several parameters. The stored procedure runs fine in SSMS, in fact it runs in seconds. However, it hangs (forever showing "Report is being Generated") when rendering in "preview" of Visual Studio.
The stored procedure accepts 4 paramenters, 3 are multi-value.
The preview works when only a few values are entered in the parameters.
The preview worked fine when I had 3 parameters (2 are multi-value); adding the 3 multivalue parameter is when the issue starts.
The report will render but it takes 20 minutes ... way too long.
Thank you for your comments