White window / Blank window freezing #10890
Description
Describe the bug
Randomly, on certain systems, WinUI 3 app shows blank window and it freezes. Only way is to end task from the Windows Task Manager.
The app runs normally otherwise. But in a day, it freezes 2-3 times.
I have 2 modes (full mode and compact mode). In compact mode I hide the menu bar, toolbar and certain grids. In full mode, I show those control back.
It appears that the freezing happen when switching between these modes. But it doesn't happen every time. It works 80% of the time. But freezes and causes annoyance to our customers that they stop using our product.
App freezes with white blank screen with mouse pointer turning to hour glass. However, I am able to resize the window. Sometimes, resizing the window brings back partial distorted content. But not most of the time.
When I lock Windows using Win+L and unlock the system, then the rendering happens and the controls are drawn. But still it is not 100% accurate. Part of the window is still undrawn.
Why is this important?
This is a great annoyance to the user because the app stops working everyday for them.
Steps to reproduce the bug
It is hard to reproduce the bug. It is not happening on our systems. It is happening on about 8 customer's systems. So there are no specific steps to reproduce. It is very challenging. I have been trying for last 3 months to reproduce. But couldn't do it.
When I lock Windows using Win+L and unlock the system, then the rendering happens and the controls are drawn. But still it is not 100% accurate. Part of the window is still undrawn.
Actual behavior
App freezes with white blank screen with mouse pointer turning to hour glass. However, I am able to resize the window. Sometimes, resizing the window brings back partial distorted content. But not most of the time.
When I lock Windows using Win+L and unlock the system, then the rendering happens and the controls are drawn. But still it is not 100% accurate. Part of the window is still undrawn.
Expected behavior
The app should run normally. All controls should be drawn correctly with proper user interaction.
Screenshots
The first 2 images are of fully blank windows. It hangs and we have to end the task from the Task Manager. When locking the Windows system using Win+L and unlocking then it would paint partially blank windows like the last 3 images below.
NuGet package version
WinUI 3 - Windows App SDK 1.8.3: 1.8.251106002
Windows version
Windows 11 (24H2): Build 26100
Additional context
I have a MenuBar, a CommandBar and a Grid that I hide bit just setting Visibility to Collapse in compact mode. The window that is narrow in the above pictures is the compact mode. In the third picture you will see "Search all folders" text box with normal size. But in the fourth picture you will see that the same text box is drawn with unexpected large size. When we type anything in the text box, it resizes back to normal size.