Question

I have a page that is based on a master page, the page has a few UpdatePanel controls and things works fine.

Problem starts when I try to update a hiddenfield control from my code behind like this –

**Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
scrollerHiddenField1.Value = getLatest10()
End Sub
Private Function getLatest10() As String
Dim db As New DataClassesDataContext

    Dim r = From p In db.LATEST10s
            Select p.carId
    Dim retString As String = ""

    For Each c As String In r
        Dim fnumber As String = Mid(c, 1, 2) & "-" & Mid(c, 3, 3) & "-" & Mid(c, 6, 2)

        retString &= fnumber & ","

    Next
    Return retString

End Function**

if getLatest10 function returns a string that has html tags inside and then I click a button I am getting the following error-

Sys.WebForms.PageRequestManagerServerErrorException: An unknown error
occurred while processing the request on the server. The status code
returned from the server was: 500

if getLatest10 function returns a string that has NO html tags inside things works fine.

Any Idea of how to solve this?

Answer 1

I’m not sure but please check if you are doing this in the right state of the page life cycle:
http://msdn.microsoft.com/en-us/library/ms178472.aspx