request failed invalid json format

[jolsen-mitsu]

Type: Bug

I asked copilot to rename xxx to yyy and aaa to bbb across multiple files it had been previously working with. It made a number of changes before getting to this point inthe output:

Now let me make the remaining updates:
Edited MIGRATION_GUIDE.md+4-4
Edited ORM_FEATURES.md+2-2
Let me handle the duplicate cases more specifically:
I see one was already updated. Let me fix the first one:

Sorry, your request failed. Please try again.
Copilot Request id: c3d472d6-4be0-44de-be0d-ecbab4fbf48c
GH Request Id: A3C1:269D5A:2579817:2B8115E:697058F4
Reason: Request Failed: 400 {"error":{"message":"Invalid JSON format in tool call arguments","code":"invalid_tool_call_format"}}
Claude Haiku 4.5

Clicking Try Again button yields the same error. All further prompts also appear to generate this error message. Looks like this chat can no longer continue due to this error.

Extension version: 0.36.1
VS Code version: Code 1.108.1 (585eba7, 2026-01-14T14:55:44.241Z)
OS version: Windows_NT x64 10.0.26200
Modes:
Remote OS version: Linux x64 6.6.87.2-microsoft-standard-WSL2

System Info

Item	Value
CPUs	11th Gen Intel(R) Core(TM) i9-11950H @ 2.60GHz (16 x 2611)
GPU Status	2d_canvas: enabled 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)	95.67GB (48.48GB free)
Process Argv	--crash-reporter-id e7f98140-221c-42ff-a3dd-68dcf6f443d9
Screen Reader	no
VM	0%

Item	Value
Remote	WSL: Ubuntu2004
OS	Linux x64 6.6.87.2-microsoft-standard-WSL2
CPUs	11th Gen Intel(R) Core(TM) i9-11950H @ 2.60GHz (16 x 0)
Memory (System)	46.88GB (36.40GB free)
VM	0%

Item	Value
Remote	WSL: Ubuntu2004
OS	Linux x64 6.6.87.2-microsoft-standard-WSL2
CPUs	11th Gen Intel(R) Core(TM) i9-11950H @ 2.60GHz (16 x 0)
Memory (System)	46.88GB (36.40GB free)
VM	0%

A/B Experiments

vsliv368cf:30146710
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31436602
aj953862:31281341
6abeh943:31336334
envsactivate1:31353494
editstats-enabled:31346257
cloudbuttont:31379625
3efgi100_wstrepl:31403338
use-responses-api:31390855
anonusage:31403420
je187915:31401254
ec5jj548:31422691
nes-oct-1007a-control:31447299
cmp-ext-treat:31426748
cp_cls_c_966_ss:31446431
c0683394:31419495
ge8j1254_inline_auto_hint_haiku:31427726
nes-autoexp-10:31446583
a5gib710:31434435
38bie571_auto:31426784
rename_enabled:31436409
7a04d226_do_not_restore_last_panel_session:31438103
anthropic_thinking_t:31432745
31c7i317_no_change:31446853
cp_cls_c_1081:31443829
copilot-nes-callisto-trt:31434411
statuswidget:31449309
nes-slash-models-on:31441832
nes-set-to-on:31441941
a43f0575b:31442825
ts_provider_disabled:31446105
nes-conv-2-2:31447849

[chrmarti]

Thanks for the detailed context. This is covered by #278912, which tracks the same invalid tool-call JSON error leaving a chat unable to process further requests. This report adds that it occurred during a multi-file rename with Claude Haiku 4.5 under WSL and persisted across Try Again and subsequent prompts.

/duplicate of #278912