Cannot resize preview pane V12.2.1

[kelvin-martin]

Describe the bug

Using Visual Studio 2022. When I click and drag the splitter between the axaml code pane and the preview pane, the splitter moves one or two pixels, then resets to where it was, leaving the splitter stuck at a 50-50 split. This happens on the horizontal layout; the vertical layout does not seem to exhibit the issue

To Reproduce

A simple single window app with MainWindow,xaml will exhibit the issue with minimal controls. It is hard to reproduce exactly. Changing the size of the VS window or maximising the IDE window, or using the previewer scroll bars, does not fix the issue. When switching to vertical view, the vertical splitter works, but returning to horizontal layout, the issue is still present.

AvaloniaVS plugin version

12.2.1

Avalonia version

12.2.1

Visual Studio version

Version 17.14.37 (July 2026)

Relevant log output

There is no log output or diagnostic messages produced.

Additional context

Restarting Visual Studio appears to resolve the issue temporarily, but it reappears after usage. The time to reappear varies.

[kelvin-martin]

Update: Moving the Solutions Explorer divider, which is adjacent to the XAML Previewer (shrinking or expanding the Solutions Explorer view), seems to 'unstick' the splitter between the Preview Pane and the Code Editor.

[mrlacey]

Hi Kelvin
I'm sorry you've encountered this.
The underlying issue is something we've been trying to work around for a long time. There have already been three updates to try to fix this issue in the last year.
Right now, the only option I have left to try to fix the problem is to replace the WPF GridSplitter with a custom implementation, which I don't want to make a high priority, as the previous fixes do seem to have stopped reports of this in VS2026.

As you've discovered, resizing the editor window (by changing the size of the app window or any other docked window) unblocks the issue (as it seemingly allows VS/WPF to correctly calculate the size of the window and so determine where the splitter should move to.

Please let us know if this continues to be a big issue and I'll see what I can do.

p.s. Sorry for the slow reply as I was on holiday

[mrlacey]

@kelvin-martin I've been having another look at this. One thing I haven't considered is the size of the window and monitor you're using, which may be very different to what we're testing on and may be affecting my ability to recreate the issue.
What are your display settings? e.g.:

• Display resolution?
• Scale?
• Number of monitors?

[kelvin-martin]

Hi, My single-screen development laptop is 1920 x 1200, with a scale setting of 125%. It's running an nVidia graphicsDirectX version: 12.0 GPU processor: NVIDIA GeForce RTX 4060 Laptop GPU Regards Kelvin

…

On Mon, 10 Aug 2026 at 10:11, Matt Lacey ***@***.***> wrote: *mrlacey* left a comment (AvaloniaUI/AvaloniaVS#649) <#649 (comment)> @kelvin-martin <https://github.com/kelvin-martin> I've been having another look at this. One thing I haven't considered is the size of the window and monitor you're using, which may be very different to what we're testing on and may be affecting my ability to recreate the issue. What are your display settings? e.g.: - Display resolution? - Scale? - Number of monitors? — Reply to this email directly, view it on GitHub <#649?email_source=notifications&email_token=ABX2XFPZ5PZYIT7KVGZWYTL5JGGU3A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMRTHAYTOMJZGQ32M4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLDGN5XXIZLSL5RWY2LDNM#issuecomment-5238171947>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABX2XFKBOWKMEZVDNMTTCB35JGGU3AVCNFSNUABEKJSXA33TNF2G64TZHM2DCNJVGA3TANB3JFZXG5LFHM2TANBRGQ3DMNBUG6QXMAQ> . Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/ABX2XFIP325MCFOUVDYANR35JGGU3A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMRTHAYTOMJZGQ32M4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJKTGN5XXIZLSL5UW64Y> and Android <https://github.com/notifications/mobile/android/ABX2XFMDULN3CCOMBNCO2LL5JGGU3A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMRTHAYTOMJZGQ32M4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLTGN5XXIZLSL5QW4ZDSN5UWI>. Download it today! You are receiving this because you were mentioned.Message ID: ***@***.***>

-- Regards Kelvin

[mrlacey]

The next release will include a fix for this..

[kelvin-martin]

Thanks, that's good Regards Kelvin

…

On Wed, 26 Aug 2026, 09:08 Matt Lacey, ***@***.***> wrote: *mrlacey* left a comment (AvaloniaUI/AvaloniaVS#649) <#649 (comment)> The next release will include a fix for this.. — Reply to this email directly, view it on GitHub <#649?email_source=notifications&email_token=ABX2XFM2HODU7T2Z6YHUAD35L2LHXA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKNBSGI2DGMZSHAY2M4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLDGN5XXIZLSL5RWY2LDNM#issuecomment-5422433281>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABX2XFM33G4ANEVUHUMPAC35L2LHXAVCNFSNUABEKJSXA33TNF2G64TZHM2DCNJVGA3TANB3JFZXG5LFHM2TANBRGQ3DMNBUG6QXMAQ> . Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS <https://github.com/notifications/mobile/ios/ABX2XFKLV6OAZ562GEVJJKT5L2LHXA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKNBSGI2DGMZSHAY2M4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJKTGN5XXIZLSL5UW64Y> and Android <https://github.com/notifications/mobile/android/ABX2XFLS4TZQ3RHSDNK2ZV35L2LHXA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKNBSGI2DGMZSHAY2M4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLTGN5XXIZLSL5QW4ZDSN5UWI>. Download it today! You are receiving this because you were mentioned.Message ID: ***@***.***>