Extension crash continuesly sinde update from April

[malfredo32]

Type: Bug

Issue Description

C# extension continuesly crashing when running Claude code extension. This begin after latest update

Steps to Reproduce

Run a prompt for coding C# with maui

Expected Behavior

FInish the changes

Actual Behavior

Claude code prompt execution is interrupted by C# engine crashing

Extension version: 2.130.5
VS Code version: Code 1.116.0 (560a9dba96f961efea7b1612916f89e5d5d4d679, 2026-04-15T00:28:13Z)
OS version: Windows_NT x64 10.0.19045
Modes:

System Info

Item	Value
CPUs	12th Gen Intel(R) Core(TM) i9-12900KF (24 x 3187)
GPU Status	2d_canvas: enabled GPU0: VENDOR= 0x10de, DEVICE=0x2182 [NVIDIA GeForce GTX 1660 Ti], DRIVER_VENDOR=NVIDIA, DRIVER_VERSION=32.0.15.6094 ACTIVE GPU1: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.19041.5794 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 webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	63.84GB (19.66GB free)
Process Argv	--crash-reporter-id 9034d1f3-a0fd-4a18-8f78-8b069819aafe
Screen Reader	no
VM	0%

A/B Experiments

vsliv368:30146709
pythonvspyt551:31249599
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
6abeh943:31336334
envsdeactivate2:31464701
cloudbuttont:31379625
3efgi100_wstrepl:31403338
use-responses-api:31390855
je187915:31401257
ec5jj548:31422691
cp_cls_t_966_ss:31454198
4je02754:31466945
c3h7c220:31478652
ge8j1254_inline_auto_hint_haiku:31490510
38bie571_auto:31478678
cp_cls_c_1081:31454833
conptydll_true:31489736
e9c30283:31461165
test_treatment2:31471001
idci7584:31464702
e3e4d672:31494082
534a6447:31478749
chat:31457767
7e187181:31496397
cpptoolsoff-v2:31475362
inline_hover_fd9bg283:31492073
23c7c724:31491644
client_tst_t:31495907
ddid_t:31478206
getcmakediagnosticsoff:31489825
cp_cls_c_1082:31491634
logging_disabled_new:31493366

[dibarbet]

@malfredo32 a couple things

1. Could you share the logs, as described here - https://github.com/dotnet/vscode-csharp/blob/release/SUPPORT.md#capturing-activity-trace-logging ?
2. We've fixed one crash in the prerelease version, with one more fix coming next week, would be good if you could try it out and let me know if it's improved.

[malfredo32]

csharp-logs-2026-04-17T20-42-30.zip

[malfredo32]

once it crashes, the claude extension gets interrupted. You can enter continue but it crash on every iteration of a c# file send to the engien

[JoeRobich]

2026-04-17 14:40:06.506 [error] [textDocument/didOpen] [LSP] Unable to parse URI _claude_vscode_fs_right:/c:/xTuple/xtuple-maui/xTuple/Models/SalesOrderModel.cs
2026-04-17 14:40:06.555 [error] [textDocument/diagnostic] [LSP] System.UriFormatException: Failed create URI from '_claude_vscode_fs_right:/c:/xTuple/xtuple-maui/xTuple/Models/SalesOrderModel.cs'; original string: '_claude_vscode_fs_right:/c:/xTuple/xtuple-maui/xTuple/Models/SalesOrderModel.cs'
 ---> System.UriFormatException: Invalid URI: The URI scheme is not valid.

This is an issue with the claude extension generating invalid URIs.