Multi line text field in SharePoint Hosted Add-In not editable

Question

I cannot edit multi line text field (plain text) in a list item. This is about SP 2013 On-Premises.

If I deploy the same Add-In to SharePoint-Online, the fields are editable.

Field-Definition:

<Field  
    ID="{7937B753-CAE7-48EC-B959-7535430E17E3}"  
    Name="ZDTDescription"  
    StaticName="ZDTDescription"  
    DisplayName="Beschreibung"  
    Type="Note"  
    RichText="FALSE"  
    NumLines="6"  
    Required="FALSE"  
    Group="X Demo Tool">  
</Field>  

The field is bound to a content type:

<FieldRef ID="{7937B753-CAE7-48EC-B959-7535430E17E3}" DisplayName="Beschreibung" Required="FALSE" Name="ZDTDescription" />  

The content type is bound to a list

<List xmlns:ows="Microsoft SharePoint" Title="XX" FolderCreation="FALSE" Direction="LTR" Url="Lists/XX" BaseType="0" xmlns="http://schemas.microsoft.com/sharepoint/" EnableContentTypes="TRUE">  
  <MetaData>  
    <ContentTypes>      
      <ContentType ID="0x0100EB40867FFF3940909FB4ED22DE1A1EE1" Name="XX" Group="Demo Tool Content Types" Description="Create a new XX" Inherits="TRUE" Version="0">  
        <FieldRefs>  
          <FieldRef ID="{7937B753-CAE7-48EC-B959-7535430E17E3}" DisplayName="Beschreibung" Required="FALSE" Name="ZDTDescription" />  
        </FieldRefs>  
      </ContentType>  
 </ContentTypes>  
    <Fields>   
      <Field ID="{fa564e0f-0c70-4ab9-b863-0177e6ddd247}" Type="Text" Name="Title" DisplayName="Model" Required="TRUE" SourceID="http://schemas.microsoft.com/sharepoint/v3" StaticName="Title" MaxLength="255" />  
      <Field ID="{7937B753-CAE7-48EC-B959-7535430E17E3}" Name="ZDTDescription" DisplayName="Beschreibung" Type="Note" NumLines="6" StaticName="ZDTDescription" RichText="FALSE" Required="FALSE" Group="X Demo Tool"></Field>  
    </Fields>  
  </MetaData>  
</List>  

If I create a new list item or open a list item in edit mode, the multi line field is not editable. The HTML-Markup is missing the data:

If I verify the list fields, list content type fields and site content type fields, everthing seems to be OK.
In a list view, I can see the value of multi line fields (added through ListInstance)

When I get the ShowInEditForm property of the field by Powershell, I get null.
If I then assign $true to ShowInEditForm, I still cannot edit the field.
If I determine the property again, PowerShell is returning true.

Please note, that everything is working, if I deploy this Add-In to SPO, no matter if I deploy it to a classic site or a modern site.

What am I missing?

Answer 1

Hi Baker Kong,

thank you very much for your quick response.
Yes, I know, it should work like this. The question is, what could cause such behaviour.
May be some sort of policy?

best regards, Ronny