Expression works in BIDS but not on Sharepoint

Question

Greetings and thanks in advance for the help, Here is my situation:

The Below script works fine in BIDS, but does not work when hosted on our sharepoint 2010 server,

=Max(Iif(Fields!Country.Value = "Total", Fields!OOS_Rate.Value, 0))

The dataset has already been rolled up, (with the country replaced by the word "Total" for the summary line) and I wanted one particular piece of data from the summary row for a table near the top of the report. I can create another dataset as a workaround, however I'm curious what is causing the issue so I can avoid it in the future.

Answer 1

This is strange, because it should work.

What result do you get?

Answer 2

#Error is the result that displays in the columns, It doesn't raise any warnings in BIDS or Report builder, it's really bizarre.