C# errors are shown in the Explorer but the editor does not highlight the error line.

Type: Feature Request

The Explorer shows that the C# file contains errors, but when I open the file, the problematic line is not visually marked with a red underline. I have to open the Problems panel and manually locate the error.

VS Code version: Code 1.138.0 (7debcd0e2acdea1c52de81bf9ee1620444407dda, 2026-09-15T07:24:32Z)
OS version: Windows_NT x64 10.0.26200
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|13th Gen Intel(R) Core(TM) i5-13600KF (20 x 3494)|
|GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x10de, DEVICE=0x1b82 [NVIDIA GeForce GTX 1070 Ti], DRIVER_VENDOR=NVIDIA, DRIVER_VERSION=32.0.15.8266 *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)|15.81GB (2.47GB free)|
|Process Argv|--crash-reporter-id f100621f-48f2-42dd-a946-eedbf67e58d4|
|Screen Reader|no|
|VM|0%|
Extensions (6)

Name|Identifier|Author|Version
---|---|---|---
Clean Code Tips|chriswingler.clean-code-tips|chriswingler|2.0.1
C# Dev Kit|ms-dotnettools.csdevkit|ms-dotnettools|3.20.207
C#|ms-dotnettools.csharp|ms-dotnettools|2.140.9
.NET Install Tool|ms-dotnettools.vscode-dotnet-runtime|ms-dotnettools|3.1.0
Live Server|ritwickdey.liveserver|ritwickdey|5.7.10
Unity|visualstudiotoolsforunity.vstuc|visualstudiotoolsforunity|1.3.1

A/B Experiments

```
vsliv368cf:30146710
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
envsactivate1:31551504
cloudbuttont:31379625
3efgi100_wstrepl:31403338
ec5jj548:31422691
cp_cls_t_966_ss:31526232
4je02754:31466945
c3h7c220:31478652
cp_cls_c_1081:31454833
conptydll_true:31498968
e9c30283:31461165
46204921:31447328
control_6dc23131:31582662
ei9d7968:31496641
chat:31457767
8hig5102:31480529
89g7j272:31518289
i2gc6536:31499202
52612955:31516516
ec1eg703:31520046
ddid_c:31478207
hmra_i5g22:31518061
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
j0d79568:31499440
jb_cp_cls_t_632:31543129
56dj4588:31512888
32d76977:31512328
ha629193:31508444
jh5f2457_c:31540921
jbcp_cls_pctr_t:31531130
cp_intellij_t_nes:31548657
jf4hg949:31526829
ahp-both-windows:31556933
ihg5j128:31534457
7g2b5551:31542111
nes-ex-cf-euporie-03:31542868
enable_editor_pane_layout:31569726
allow-none:31555437
ac562147:31564510
c7c27ce7:31554789
1h923230:31564177
treatment-23-1:31555779
unuse_dynamic_mcp:31555281
0d8dfbc3:31570291
nemo-v2:31565334
0c1h4866:31566224
session-archive:31558132
5b8j3302:31564601
autotiers:31584978
mangle-name-control:31572633
allow-signed-out:31584137
intellij_nes_preview_t:31580086
39a5d156:31574986
2bfb8b39:31576696
soft:31581111
aw-autom-on:31583758
revealsession_control_7ed7e840:31582193
4ab0b639:31584543
codex-agent-host-stable-control:31585316
permission_prompt_treatment:1332566
ccr_pr_nudge_adoption:1319471
vsc_wsm_t:1340632
h5e14506_copy:1348995
cfee5631:1379228
3aced641:1389836

```