Repeater: Working in one template, not working in another ("Invalid value for $existingItem argument") - SOLVED

[MichaelHafner]

Hi all!

ProcessWire 3.0.200

1.) I use one repeater in two templates.

2.) The setup is the same in both cases: No access control for the template, no access control for the field.

3.) No problem in using the repeater via API in both templates.

BUT:

4.) In one template, I can (via Admin backend) add, edit, and delete repeater items (whether the repeater is populated or not.)

5.) In the other template, I can edit existing repeater items (whether the repeater is populated or not). I cannot, however, add new items. 

6.) exceptions.txt says: "2026-10-11 19:04:29    admin   https://vfm-online.de/cms/processwire/processwire/page/edit/?id=1063&field=person_adresse&repeater_add=1&repeater_not=1158_1253_  Invalid value for $existingItem argument (in /wire/core/InputfieldWrapper.php line 424)"

7.) But what does that tell me? And why does the error occur with *all* records belonging to this template and never with records from the other?

It used to work...  - I'm lost. Anybody who could give me a hint?

Best & thank-you

Michael

 

 

 

 

Edited 16 hours ago by MichaelHafner

[MichaelHafner]

In log entry...

2026-10-15 15:43:48    admin   https://vfm-online.de/cms/processwire/processwire/page/edit/?id=1063&field=person_adresse&repeater_add=1&repeater_not=1158_1253_  Invalid value for $existingItem argument (in /wire/core/InputfieldWrapper.php line 424)

1063 is the id of the repeater's parent, 1158_1253_ are the concatenated ids of the two existing repeater items. 

On a page with no existing repeater items, the log entry looks like this:

2026-10-15 15:50:25    admin   https://vfm-online.de/cms/processwire/processwire/page/edit/?id=142467&field=person_adresse&repeater_add=1  Invalid value for $existingItem argument (in /wire/core/InputfieldWrapper.php line 424)

But what can I do with that? I won't do any good to look into /wire/core/InputfieldWrapper.php, as it can't be a bug. 

I'm a little desperate as this occurred, out of the blue, in a productive system. Now we can add persons to our register, but we can't write down their addresses. 

 

 

 

[MichaelHafner]

Solved it, but I still have to figure out, why. Or how. 😄

I had added a button before another form field (v.i.). Seems by doing so I made the button a form field (which, actually, prevented any repeater item from being created, not just addresses)? But why, then, didn't the form stop working at all?! - Anyway, I put the button before the submit button, et voilà.

  public function otlet_addbuttons ($event) {
    $page = $event->object->getPage();
    switch ($page->template->name) {
    case "vfm_person":
      if($page->get('remote_addr') != '') {
        $form = $event->return;
        if(!$form->get('otlet_put_ip_on_blacklist')) {
          $button_1_text = __("IP auf Sperrliste");
          $button_1 = $this->modules->InputfieldSubmit;
          $button_1->attr("value", $button_1_text);
          $button_1->attr("name", "otlet_put_ip_on_blacklist");
          // Doesn't work
          # $form->insertBefore($button_1, $form->get("remote_addr"));
          // Works
          $form->insertBefore($button_1, $form->get("submit_save"));
        } 
      }
    }
  }