Q:

SSRS report fails to load in browser report manager - rsFilterEvaluationError

The ssrs report uses a filter in the tablix properties. 
The report is successfully generated in the visual studio preview but when i try to generate the preview in browser (chrome, IE) via the reporting manager, i receive the following error.

Failed to evaluate the FilterExpression Tablix "Tablix2". (rsFilterEvaluationError)

Might not be the 100% correct error message bc i got them in german.
Expression (date type): =Cdate(Format(CDate(Right(Trim(Fields!CustomerReqDate.Value),2) & "." & Mid(Trim(Fields!CustomerReqDate.Value),5,2) & "." & Left(Trim(Fields!CustomerReqDate.Value), 4)), "dd.MM.yyyy"))
Operator: <=
Value: =Cdate(Format(DateAdd("d",42,Now), "dd.MM.yyyy"))

A:

Since it works in preview but not the browser it may have to do with localization settings. I'm assuming CustomerReqDate is a string in the form of "YYYYMMDD". Try using this expression instead:
=DateSerial(Left(Trim(Fields!CustomerReqDate.Value), 4)
    , Mid(Trim(Fields!CustomerReqDate.Value),5,2)
    , Right(Trim(Fields!CustomerReqDate.Value),2))

And just use the DateAdd function, don't worry about formatting and conversions.
=DateAdd("d",42,Now)

This should allow SSRS to compare a date to a date regardless of the local format.

