Razor formatting fails with overlapping changes

[Akhtaruzzaman]

Type: Bug

Issue Description

Steps to Reproduce

Expected Behavior

Actual Behavior

Extension version: 2.140.9
VS Code version: Code 1.136.1 (a44adf7f53e00964ab890f9f8758a334f1fc15bc, 2026-09-03T05:06:41Z)
OS version: Windows_NT x64 10.0.26200
Modes:

Logs

C# log

Details

2026-09-04 13:50:09.901 [info] Locating .NET runtime version 10.0.5
2026-09-04 13:50:09.995 [info] Dotnet path: C:\Program Files\dotnet\dotnet.exe
2026-09-04 13:50:09.995 [info] Activating C# + C# Dev Kit...
2026-09-04 13:50:10.225 [info] info: Program[0]
2026-09-04 13:50:10.225 [info]       Server started with process ID 33380
2026-09-04 13:50:11.008 [info] [Program] Language server initialized
2026-09-04 13:50:11.009 [info] [Program] Monitoring client process 17020 for exit
2026-09-04 13:50:11.466 [info] [initialized] [Microsoft.CodeAnalysis.LanguageServer.FileBasedPrograms.FileBasedProgramsEntryPointDiscovery] Finished discovery in 'd:\WorkStation\mr-logistics' in 14 milliseconds
2026-09-04 13:50:14.870 [info] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\WorkStation\mr-logistics\Repository\Repository.csproj loaded by C# Dev Kit
2026-09-04 13:50:14.910 [info] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\WorkStation\mr-logistics\Domain\Domain.csproj loaded by C# Dev Kit
2026-09-04 13:50:14.914 [info] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\WorkStation\mr-logistics\Application\Application.csproj loaded by C# Dev Kit
2026-09-04 13:50:14.916 [info] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\WorkStation\mr-logistics\Application.Test\Application.Test.csproj loaded by C# Dev Kit
2026-09-04 13:50:14.921 [info] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\WorkStation\mr-logistics\Common.Library\Common.Library.csproj loaded by C# Dev Kit
2026-09-04 13:50:14.922 [info] [serviceBroker/connect] [WorkspaceProjectFactoryService] Project D:\WorkStation\mr-logistics\Web\Web.csproj loaded by C# Dev Kit
2026-09-04 14:29:18.544 [error] Request textDocument/formatting failed.
  Message: The changes must not overlap. (Parameter 'changes')
  Code: -32000 
[object Object]
2026-09-04 14:29:35.611 [error] Request textDocument/formatting failed.
  Message: The changes must not overlap. (Parameter 'changes')
  Code: -32000 
[object Object]

C# LSP Trace Logs log

Details

Environment Information

VSCode version: 1.136.1
C# Extension: 2.140.9
Using OmniSharp: false

Dotnet Information

.NET SDK: Version: 10.0.400 Commit: 14fbf8d527 Workload version: 10.0.400-manifests.b0ae88bd MSBuild version: 18.9.6+14fbf8d52

Runtime Environment:
OS Name: Windows
OS Version: 10.0.26200
OS Platform: Windows
RID: win-x64
Base Path: C:\Program Files\dotnet\sdk\10.0.400\

.NET workloads installed:
There are no installed workloads to display.
Configured to use workload sets when installing new manifests.
No workload sets are installed. Run "dotnet workload restore" to install a workload set.

Host:
Version: 10.0.11
Architecture: x64
Commit: e2f47b0110

.NET SDKs installed:
2.2.207 [C:\Program Files\dotnet\sdk]
6.0.428 [C:\Program Files\dotnet\sdk]
8.0.424 [C:\Program Files\dotnet\sdk]
10.0.400 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.All 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 10.0.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.2.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 10.0.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 6.0.36 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.30 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 10.0.11 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
x86 [C:\Program Files (x86)\dotnet]
registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
DOTNET_CLI_UI_LANGUAGE [en-US]

global.json file:
Not found

Learn more:
https://aka.ms/dotnet/info

Download .NET:
https://aka.ms/dotnet/download

Visual Studio Code Extensions

Extension	Author	Version	Folder Name
Angular2	johnpapa	22.0.0	johnpapa.angular2-22.0.0
csdevkit	ms-dotnettools	3.20.199	ms-dotnettools.csdevkit-3.20.199-win32-x64
csharp	ms-dotnettools	2.140.9	ms-dotnettools.csharp-2.140.9-win32-x64
debugpy	ms-python	2026.6.0	ms-python.debugpy-2026.6.0-win32-x64
es7-react-js-snippets	dsznajder	4.4.3	dsznajder.es7-react-js-snippets-4.4.3
material-icon-theme	PKief	5.38.1	pkief.material-icon-theme-5.38.1
ng-template	Angular	22.1.0	angular.ng-template-22.1.0
prettier-vscode	esbenp	12.4.0	esbenp.prettier-vscode-12.4.0
python	ms-python	2026.4.0	ms-python.python-2026.4.0-win32-x64
vscode-dotnet-runtime	ms-dotnettools	3.1.0	ms-dotnettools.vscode-dotnet-runtime-3.1.0
vscode-eslint	dbaeumer	3.0.34	dbaeumer.vscode-eslint-3.0.34
vscode-pylance	ms-python	2026.3.1	ms-python.vscode-pylance-2026.3.1
vscode-python-envs	ms-python	1.36.0	ms-python.vscode-python-envs-1.36.0-win32-x64
vscode-react-native	msjsdiag	1.13.0	msjsdiag.vscode-react-native-1.13.0

C# Settings

Setting	Value
preferCSharpExtension	false
compilerDiagnosticScope	openFiles
analyzerDiagnosticScope	openFiles
enableXamlTools	true
useServerGC	true

System Info

Item	Value
CPUs	12th Gen Intel(R) Core(TM) i5-12500H (16 x 3110)
GPU Status	2d_canvas: enabled GPU0: VENDOR= 0x8086, DEVICE=0x46a6 [Intel(R) Iris(R) Xe Graphics], DRIVER_VENDOR=Intel, DRIVER_VERSION=31.0.101.4255 ACTIVE GPU1: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.9278 Machine model name: Machine model version: direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off trees_in_viz: disabled_off video_decode: enabled video_encode: enabled webgl: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	23.70GB (4.94GB free)
Process Argv	--crash-reporter-id 13c236eb-63e4-46d5-b7c7-a7e5ab7efc29
Screen Reader	no
VM	40%

A/B Experiments

vsliv368cf:30146710
pythonvspyt551cf:31249601
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
82j33506:31327384
envsactivate1:31551504
cloudbuttont:31379625
3efgi100_wstrepl:31403338
ec5jj548:31422691
diffpatch-lysithea-24-production:31578711
cp_cls_t_966_ss:31526232
4je02754:31466945
8hhj4413:31478653
ge8j1254_inline_auto_hint_haiku:31490510
cp_cls_t_1081:31454832
conptydll_true:31498968
e9c30283:31461165
46204921:31447328
control_6dc23131:31576178
ei9d7968:31496641
chat:31457767
8hig5102:31480529
89g7j272:31518289
i2gc6536:31499202
52612955:31516516
ddid_t:31478206
hmra_i5g22:31518061
ja75b849:31575055
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
db5d2638:31499441
jb_cp_cls_t_632:31543129
56dj4588:31512888
32d76977:31512328
ha629193:31508444
a1ije391_t:31540920
jbcp_cls_pctr_t:31531130
cp_intellij_t_nes:31548657
gf14b233:31526830
ahp-both-windows:31556933
ihg5j128:31534457
9gg7f176:31542112
enable_editor_pane_layout:31569726
allow-none:31555437
ac562147:31564510
c7c27ce7:31554789
1h923230:31564177
0dg73464:31554319
treatment-23-1:31555779
unuse_dynamic_mcp:31555281
0d8dfbc3:31570291
a1hcc538:31559322
nemo-v2:31565334
0c1h4866:31566224
vrbsty_tr:31561058
session-mark-done:31558131
5b8j3302:31564601
mangle-name-control:31572633
multiv2:31574985
2bfb8b39:31576696
permission_prompt_treatment:1332566
ccr_pr_nudge_adoption:1319471
vsc_wsm_c:1340633
jidc7660:1370295
auto_mode_control:1367906

[dibarbet]

Thanks for the report. The log shows Razor document formatting failing with The changes must not overlap.

A fix for this exact Razor error in one known scenario (long/multiline Razor comments and related HTML formatting edits) was included in C# extension 2.146.x. You are using 2.140.9. Could you first retry with the latest C# pre-release/current version (2.146 or newer)?

If it still reproduces, please attach:

• the smallest .razor or .cshtml file that triggers it;
• the Razor formatter logs described at https://aka.ms/razor-formatting-issue; and
• whether html.format.preserveNewLines is disabled or the file contains long multiline Razor comments.