The run button at the top right corner doesn't work anymore

Type: Bug

The play button at the top right corner of VSCode when working on C# project no longer starts running and debugging my files (since VSCode updated, worked fine yesterday). f5 still works, and so does dotnet run in the terminal. I have uninstalled and reinstalled my extensions and vscode for that matter, restarted my pc, etc and the problem still persists.

Extension version: 3.1.0
VS Code version: Code 1.137.0 (645f29cc3176500b4b5762ba887cf2a7f0ffdf2c, 2026-09-08T13:43:59-07:00)
OS version: Windows_NT x64 10.0.19045
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|Intel(R) Core(TM) i3-8100 CPU @ 3.60GHz (4 x 3600)|
|GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x1002, DEVICE=0x67ef [Radeon Pro 555X], DRIVER_VENDOR=AMD, DRIVER_VERSION=27.20.14540.15002 *ACTIVE*
GPU1: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.19041.7548
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)|15.88GB (10.98GB free)|
|Process Argv|--crash-reporter-id 23743743-4f6b-4463-a0ae-496708e31099|
|Screen Reader|no|
|VM|0%|

Reproduce the failure in VS Code 1.137.0 with extension version 3.1.0 on a C# project, comparing the top-right play button with F5 and `dotnet run`. No repository file or test is named, so first identify the extension entry point handling the run/debug button and confirm the expected behavior: the button should start running and debugging the project.

Written by the indexing model from the issue text.