I want to use a Trigger event for an Update Panel that is being bound by a repeater, error: The ControlID property must be set on the trigger in UpdatePanel

i got dificulty to understant what you mean, but here my advice.
dont put any trigger on the update panel, keep it conditional = true (a chlidrenastrigger false)
on the OnClick function, use the updatepanel.update() function to "trigger" the update

Okay so far my updatePanel I now have:

 <asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="server" ChildrenAsTriggers="false">
        <ContentTemplate>
       
        </ContentTemplate>
    </asp:UpdatePanel>

And for my code behind I have:
    Public Sub setClick()
        test.Text = "yup"
        UpdatePanel1.Update()
    End Sub

Is this what you mean?

yes
but "test" label or textbox should be inside your ContentTemplate...

Oops, yes indeed it should.   I am getting this error when I run it and click on the Link...

Invalid postback or callback argument.  Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page.  For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them.  If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.

I do not want to turn Off my Event Validation though for this to work.... any suggestions?

well, it<s because you "created" the images buttons in the Page_Load.

1. test, if you remove the avlidation, just to make sure it works without it, then pput it back
2. check if you could "build" your repeater an other way. if your reapeter is declared on the aspx page and is only "binded" on page load, it should work.

avlidation = EventValidation

You were correct again I just put a If Not IsPostBack around the repeater.... and it works to some extent.

The OnClick function is refreshing the the whole page and not just my UpdatePanel section..

That worked perfectly.. Thank you for allllll your help :)

it was a pleasure, thanks for the grade, and next time add Ajax in your Zones.