Adding Site Collection Owners

Question

I'm trying to add an account to the site collection owners on users personal sites. I'm using the following:

User spUser = null;
using (ClientContext clientContext = new ClientContext(siteURL)) {
    clientContext.Credentials = credentials;
    if (clientContext != null)
    {
        spUser = clientContext.Web.EnsureUser(userAccount);
        spUser.IsSiteAdmin = true;
        spUser.Update();

        clientContext.Load(spUser);
        clientContext.ExecuteQuery();
    }
}

but I'm getting this error:

You need to be a site collection administrator to set this property.

On the Sharepoint site, the user is under site collection Administrators.

I'm also looking to do this from a console application.

Answer 1

The error You need to be a site collection administrator to set this property occurs when one of the following conditions does not met:

• Ensure the user performing a request is a Site Collection Administrator
• Ensure permissions for the App, explicitly request FullControl permission at the Site Collection scope as shown below:

Follow Adding Site Collection Admin in CSOM in a SharePoint 2013 App article for a more details.