SAPUI5 OData binding to table - data-binding

Question

I try to bind campaign data from the OData service CUAN_CAMPAIGN_SRV to a TableSelectDialog element. In my view I have an Input field with input help:
<form:FormElement visible="true">
<form:label>
<Label text="Campaign" design="Standard" width="100%" required="false" textAlign="Begin" textDirection="Inherit"/>
</form:label>
<form:fields>
<Input id="campaignId" type="Text" enabled="true" visible="true" width="auto" editable="true" showValueHelp="true" valueHelpOnly="true" valueHelpRequest="handleValueHelp"/>
</form:fields>
The value help calls the function handleValueHelp in my controller:
handleValueHelp: function(oController) {
this.inputId = oController.oSource.sId;
// create value help dialog
if (!this._valueHelpDialog) {
this._valueHelpDialog = sap.ui.xmlfragment(
"my.view.Campaigns",
this
);
this.getView().addDependent(this._valueHelpDialog);
}
// open value help dialog
this._valueHelpDialog.open();
}
This is when my table dialog (fragment) pops up:
<core:FragmentDefinition xmlns="sap.m" xmlns:core="sap.ui.core">
<TableSelectDialog id="campaignSelect" title="Select campaign" items="{path:'/CampaignSet'}" growingThreshold="5">
<columns>
<Column>
<Text text="Name"/>
</Column>
<Column>
<Text text="ID"/>
</Column>
<Column>
<Text text="Created at"/>
</Column>
<Column>
<Text text="Created by"/>
</Column>
</columns>
<items>
<ColumnListItem>
<Text text="{CampaignName}"/>
<Text text="{CampaignId}"/>
<Text text="{CreatedOn}"/>
<Text text="{CreatedBy}"/>
</ColumnListItem>
</items>
</TableSelectDialog>
So I tried to bind the EntitySet CampaignSet from OData Service CUAN_CAMPAIGN_SRV to the table. Therefore I added this code to my init() function of the controller:
var uname = "UNAME";
var pw = "PW";
var oModel = new sap.ui.model.odata.v2.ODataModel("https://host:port/sap/opu/odata/sap/CUAN_CAMPAIGN_SRV/",
true, uname, pw);
this.getView().setModel(oModel);
The problem is: the table contains no data and this error shows up in the console:
Translated from german: "In the context of Data Services an unknown internal server error occured"
iwfnd/error_log says this:
Invalid format (return table): Row Number 1, Property Name
'ChangedOn', Property Value '0 '
Why does ChangedOn even matter if I don't want to bind this property?
I can call something like below directly in browser with success:
https://host:port/sap/opu/odata/sap/CUAN_CAMPAIGN_SRV/CampaignSet('100001625')/CampaignName
What do I do wrong? Thank you for every hint!
ChangedOn is set to Nullable in the service definition: