Builder Id / SSO page fails ("couldn't complete your request")

Type: Bug

In AWS Toolkit,I does not sign in Code whispere.In sign Up i give my Email and Password,But it will show Error
it's not you,it's
For past one month it will show this type of Error.

Extension version: 2.16.0
VS Code version: Code 1.87.2 (863d2581ecda6849923a2118d93a088b0745d9d6, 2024-03-08T15:20:17.278Z)
OS version: Windows_NT x64 10.0.22631
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|11th Gen Intel(R) Core(TM) i3-1115G4 @ 3.00GHz (4 x 2995)|
|GPU Status|2d_canvas: enabled
canvas_oop_rasterization: enabled_on
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
video_decode: enabled
video_encode: enabled
vulkan: disabled_off
webgl: enabled
webgl2: enabled
webgpu: enabled|
|Load (avg)|undefined|
|Memory (System)|7.70GB (0.81GB free)|
|Process Argv|--crash-reporter-id 7f492fd0-6445-4baa-bc52-4dcfdecadce1|
|Screen Reader|no|
|VM|0%|

A/B Experiments

```
vsliv368:30146709
vspor879:30202332
vspor708:30202333
vspor363:30204092
vswsl492:30256859
vstes627:30244334
vscoreces:30445986
vscod805cf:30301675
binariesv615:30325510
vsaa593cf:30376535
py29gd2263:30899288
c4g48928:30535728
azure-dev_surveyone:30548225
a9j8j154:30646983
962ge761:30959799
pythongtdpath:30769146
welcomedialogc:30910334
pythonidxpt:30866567
pythonnoceb:30805159
asynctok:30898717
pythontestfixt:30902429
pythonregdiag2:30936856
pyreplss1:30897532
pythonmypyd1:30879173
pythoncet0:30885854
h48ei257:30998030
pythontbext0:30879054
accentitlementsc:30995553
dsvsc016:30899300
dsvsc017:30899301
dsvsc018:30899302
cppperfcontrol:30979541
d34g3935:30971562
fegfb526:30981948
bg6jg535:30979843
ccp2r6:30993542
dsvsc020:30976470
pythonaic:30996667
dsvsc021:30996838

```

Start by reproducing the Builder ID or SSO sign-in failure using the reported AWS Toolkit extension 2.16.0, VS Code 1.87.2, and Windows 10 environment. The issue names no source file, test, or diagnostic output, so first identify the sign-in entry point and relevant logs; done means the reported request-completion error is understood and the sign-in flow works or fails with actionable feedback.

Written by the indexing model from the issue text.