Resolving the GUI Window tried to begin rendering Error in Unity Editor

Описание: Discover how to fix the `GUI Window tried to begin rendering while something else had not finished rendering` error in Unity. Learn effective solutions and best practices to enhance your Unity experience.
---
This video is based on the question https://stackoverflow.com/q/68308013/ asked by the user 'Daniel Lip' ( https://stackoverflow.com/u/847881/ ) and on the answer https://stackoverflow.com/a/68308403/ provided by the user 'leo Quint' ( https://stackoverflow.com/u/4671992/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to resolve this error ? GUI Window tried to begin rendering while something else had not finished rendering

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Resolving the GUI Window tried to begin rendering Error in Unity Editor

If you’re a Unity developer, you might have encountered a frustrating error message in the editor that states: "GUI Window tried to begin rendering while something else had not finished rendering!" This issue often leads to confusion as it doesn’t specify a line number or script name, leaving developers to troubleshoot in the dark. In this post, we'll break down the problem and provide a clear solution to help you resolve this error efficiently.

Understanding the Error

What Causes the Error?

Concurrent Rendering: The error indicates that the inspector might be attempting to render new GUI elements while still processing previously rendered ones.

Layout Changes: Changes in the inspector’s layout while rendering occurs could trigger this error—especially if the layout modifications involve adding or removing GUI elements like tags or layers.

Why It Matters

Ignoring this error can hinder your workflow and lead to unexpected behavior in your Unity projects. It’s crucial to resolve this if you want a streamlined editing experience without interruptions.

Solution to the Error

To fix the error, you can utilize the EditorApplication.delayCall delegate, which ensures that certain actions are only executed after all GUI updates have been completed. This technique helps to prevent conflicting rendering tasks.

Implementation Steps

Follow these steps to adjust your existing script and eliminate the error:

Modify the OnInspectorGUI Method: Replace the existing logic for button actions that modify the GUI with delayed calls.

Here's the updated version of your script:

[[See Video to Reveal this Text or Code Snippet]]

Understand the Changes:

The EditorApplication.delayCall allows you to queue the actions to be executed after the current GUI render cycle is complete. This avoids the potential recursive rendering that leads to the error.

Test the Functionality:

After implementing the changes, rerun your Unity Editor and test the buttons to create and remove tags/layers. Ensure that the error message no longer appears and that the buttons function correctly.

Conclusion

By using the EditorApplication.delayCall delegate, you can effectively manage GUI updates in the Unity Editor, preventing the "GUI Window tried to begin rendering..." error. This adjustment not only enhances the stability of your custom editor script but also ensures a smoother development workflow.

Make sure to implement these best practices to reduce errors and improve your Unity experience. Happy developing!