# \[BUG\] Unable to render CSS Layers in Themes

**URL:** <https://forum.inductiveautomation.com/t/bug-unable-to-render-css-layers-in-themes/104388>\
**Category:** Ignition\
**Tags:** perspective\
**Created:** [March 28, 2025, 4:18pm UTC](https://forum.inductiveautomation.com/t/bug-unable-to-render-css-layers-in-themes/104388 "2025-03-28T16:18:18Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![kgamble](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kgamble/32/8019_2.png) [@kgamble](https://forum.inductiveautomation.com/u/kgamble)\
**Post date:** [March 28, 2025, 4:18pm UTC](https://forum.inductiveautomation.com/t/bug-unable-to-render-css-layers-in-themes/104388/1 "2025-03-28T16:18:18Z")

</div>

I am trying to do some stuff that leverages CSS layers, however whenever I try to add a layer to the native `light.css` or `dark.css` themes it gives me a null pointer when trying to strip comments from the CSS.

I am guessing this is a bug, unfortunately, but any ideas how to achieve the same goal?

### modules/com.inductiveautomation.perspective/themes/light.css

```css
@import "./light/index.css" layer(ignition);

```

### The NPE

```python
java.lang.NullPointerException: Cannot invoke "String.replaceAll(String, String)" because "css" is null

at com.inductiveautomation.perspective.gateway.assets.themes.ThemeManagerImpl.removeComments(ThemeManagerImpl.java:421)

at com.inductiveautomation.perspective.gateway.assets.themes.ThemeManagerImpl.processTheme(ThemeManagerImpl.java:258)

at com.inductiveautomation.perspective.gateway.assets.themes.ThemeManagerImpl.lambda$onCacheChanged$5(ThemeManagerImpl.java:248)

at java.base/java.util.HashMap.forEach(Unknown Source)

at com.inductiveautomation.perspective.gateway.assets.themes.ThemeManagerImpl.onCacheChanged(ThemeManagerImpl.java:246)

at com.inductiveautomation.perspective.gateway.assets.AbstractAssetManager.onCreateOrModify(AbstractAssetManager.java:481)

at com.inductiveautomation.perspective.gateway.assets.AbstractAssetManager.onWatchEvent(AbstractAssetManager.java:160)

at com.inductiveautomation.perspective.gateway.files.FileWatcher.processWatchEvent(FileWatcher.java:204)

at com.inductiveautomation.perspective.gateway.files.FileWatcher.lambda$processWatchKey$0(FileWatcher.java:234)

at java.base/java.util.ArrayList.forEach(Unknown Source)

at com.inductiveautomation.perspective.gateway.files.FileWatcher.processWatchKey(FileWatcher.java:234)

at com.inductiveautomation.perspective.gateway.files.FileWatcher.processFileChanges(FileWatcher.java:260)

at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)

at java.base/java.util.concurrent.FutureTask.run(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)

at com.inductiveautomation.perspective.gateway.threading.BlockingWork$BlockingWorkRunnable.run(BlockingWork.java:58)

at java.base/java.lang.Thread.run(Unknown Source)

```

Essentially I have some other theming I want to prioritize, that is using layering, and I want it to take precedence over the native themes.

```css
@layer ignition, theme, base, components, utilities;

```

---

<div class="post-metadata">

**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [March 28, 2025, 4:20pm UTC](https://forum.inductiveautomation.com/t/bug-unable-to-render-css-layers-in-themes/104388/2 "2025-03-28T16:20:24Z")

</div>

I think the layer/etc stuff is a red herring. The NPE suggests we weren't able to load the root CSS file from disk at all.

---

<div class="post-metadata">

**Author:** ![kgamble](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kgamble/32/8019_2.png) [@kgamble](https://forum.inductiveautomation.com/u/kgamble)\
**Post date:** [March 28, 2025, 4:32pm UTC](https://forum.inductiveautomation.com/t/bug-unable-to-render-css-layers-in-themes/104388/3 "2025-03-28T16:32:49Z")

</div>

Hmm... I hear that...

However, it loads totally fine when the `light.css` file only includes

```css
@import "./light/index.css";

```

but as soon as I make it

```css
@import "./light/index.css" layer(ignition);

```

The next time it attempts to refresh the file it starts throwing a 404 in the browser and throwing this error

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/d/4/d4d730a8726fd636ece8a2a660222dbf3ebaae4d.png)

Then if I remove the `layer(ignition)` part, the next time it scan the themes it returns to normal