# Designer View Open Error

**URL:** <https://forum.inductiveautomation.com/t/designer-view-open-error/113322>\
**Category:** Ignition\
**Tags:** perspective, ignition83, designer\
**Created:** [January 15, 2026, 4:59pm UTC](https://forum.inductiveautomation.com/t/designer-view-open-error/113322 "2026-01-15T16:59:00Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![marco.handle](https://avatars.discourse-cdn.com/v4/letter/m/7ab992/32.png) [@marco.handle](https://forum.inductiveautomation.com/u/marco.handle)\
**Post date:** [January 15, 2026, 4:59pm UTC](https://forum.inductiveautomation.com/t/designer-view-open-error/113322/1 "2026-01-15T16:59:00Z")

</div>

Hi everyone,

we have a Problem with the designer.

If I want to open a View then the View is stuck in initializing.

In the console of the designer the following message is shown:

```python
17:55:00.220 [Browser Thread: b8e8e7cc-be88-4bca-b672-6d3a44ca71a8] ERROR Perspective.Designer.Workspace -- level: LEVEL_ERROR
message: "store.Client: Hello API call failed. Code=ERR_BAD_REQUEST. Status=400. Message=Request failed with status code 400"
line_number: 2
source: "https://ignition1.xxxxx/res/perspective/js/PerspectiveClient.3cf0a4e1f3ecd1e92afc.js"

```

If I then close the view I got this error:

```python
java.util.concurrent.ExecutionException: java.lang.IllegalArgumentException: Unexpected return type; expected string, got null

```

If I make a new view and save it, all is work fine and I also can reopen the view an do changes. The perspective sessions all work very well.

I hope you could help us. It is since some hours. For developing we use git, and our local instances work fine. Only the productive and test instance are showing this problems.

All ignition gateways are running in docker container wit the version 8.3.2

Thanks for your help.

---

<div class="post-metadata">

**Author:** ![tgarrison](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/tgarrison/32/80965_2.png) [@tgarrison](https://forum.inductiveautomation.com/u/tgarrison)\
**Post date:** [January 15, 2026, 8:21pm UTC](https://forum.inductiveautomation.com/t/designer-view-open-error/113322/2 "2026-01-15T20:21:47Z")

</div>

I can't help you, but if you need quick support, you shouldn't rely on these forums. Best to call Ignition Tech Support directly and open a ticket with them.

---

<div class="post-metadata">

**Author:** ![marco.handle](https://avatars.discourse-cdn.com/v4/letter/m/7ab992/32.png) [@marco.handle](https://forum.inductiveautomation.com/u/marco.handle)\
**Post date:** [January 15, 2026, 9:31pm UTC](https://forum.inductiveautomation.com/t/designer-view-open-error/113322/3 "2026-01-15T21:31:34Z")

</div>

I recently found the Problem.

It is the reverse proxy traefik.

With the version of 3.6.4 it introduced that the proxy answer with Error Code 400 if an encoded Slash is in the url.

> **[v3.6.4 - Traefik Migration Documentation - Traefik](https://doc.traefik.io/traefik/v3.6/migrate/v3/#v364)**
>
> This guide provides detailed migration steps for upgrading between different Traefik v3 versions. Each section covers breaking changes, deprecations, and configuration updates required for a smooth transition. | Learn the steps needed to migrate to...