Bug SceneView.MouseDown popup window every time i work on terrain

Hi everyone,

when working on a terrain with a couple of textures, i have this window that opens everytime i click to paint texture or raise/lower terrain.

See picture

It says: HOLD ON
SceneView.MouseDown
Waiting for Unity's code in unityEditor.CoreModule.dll to finish executing.

Any idea what might be causing that? If i reload unity, still does it. No need to tell you it makes it impossible working in Unity terrain editor :-(

thanks for your help

 

You're not alone. There are threads with hundreds of messages that might be helpful, such as:

https://forum.unity.com/threads/editor-progress-bar-stalls-request-for-bug-reports.1137817/

https://forum.unity.com/threads/improving-iteration-time-on-c-script-changes.1184446/

And hundreds of other threads.

Good luck.