Kiro is having trouble responding right now: 0: Failed to send the request: An unknown error occurred: ValidationException 1: An unknown error occurred: ValidationException 2: unhandled error (ValidationException) 3: service error 4: unhand

[mahindc]

Checks

• I have searched github.com/aws/amazon-q-developer-cli/issues and there are no duplicates of my issue
• I have run q doctor in the affected terminal session
• I have run q restart and replicated the issue again

Operating system

macOS 26.2.0 (25C56)

Expected behaviour

It allows me to allocate more cache. Has cache management where anything older it ages to file and continues to work on my current requests. It should be able to fix the errors on its own and let me work without nasty feedback on screen

Actual behaviour

This was working till last week. This week, it has kept giving me this error since morning for multiple interfaces.
The cache has started running out like after 1 command from 4% to 98%.

Steps to reproduce

No response

Environment

<This will be visible to anyone. Do not include personal or sensitive information>

[q-details]
version = "1.26.0"
hash = "efa4a1819cc7fe8f2a556aed24db114e3ddd46c2"
date = "2026-02-13T03:42:07.610083Z (4d ago)"
variant = "full"

[system-info]
os = "macOS 26.2.0 (25C56)"
chip = "Apple M3 Pro"
total-cores = 11
memory = "18.00 GB"

[environment]
cwd = "/Users/USER/mydocs/MDTHINK/021626"
cli-path = "/Users/USER/mydocs/MDTHINK/021626"
os = "Mac"
shell-path = "/bin/zsh"
shell-version = "5.9"
terminal = "macOS"
install-method = "unknown"

[env-vars]
PATH = "/Users/USER/.volta/bin/:/Users/USER/.venv/bin:/opt/homebrew/bin:/opt/homebrew/sbin:/Library/Frameworks/Python.framework/Versions/3.12/bin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/opt/pmk/env/global/bin:/usr/local/go/bin:/Applications/quarto/bin:/Users/USER/.volta/bin:/Users/USER/.cargo/bin:/Users/USER/.local/bin:/Applications/Visual Studio Code.app/Contents/Resources/app/bin:/Users/USER/.toolbox/bin"
QTERM_SESSION_ID = "12f1dabc341f4338a263b5ec0f9e7bfd"
Q_SET_PARENT_CHECK = "1"
Q_TERM = "1.26.0"
SHELL = "/bin/zsh"
TERM = "xterm-256color"
__CFBundleIdentifier = "com.apple.Terminal"

[ns-rkusumoto]

`Model: auto (/model to change) | Plan: KIRO PRO (/usage for more detail)

without an kiro-cli update last week, it complained that mcp.json was using a servers stanza vs mcpServers, edited that and got similar errors:

22% > want to fix dynatrace problems or change thresholds

Kiro is having trouble responding right now:
0: Failed to send the request: An unknown error occurred: ValidationException
1: An unknown error occurred: ValidationException
2: unhandled error (ValidationException)
3: service error
4: unhandled error (ValidationException)
5: Error { code: "ValidationException", message: "Improperly formed request.", aws_request_id: "aa4beeae-214c-45f6-b1f5-04c8448eb026" }

Location:
crates/chat-cli/src/cli/chat/mod.rs:1467

BACKTRACE
5 frames hidden
6: chat_cli::cli::chat::ChatSession::next::{{closure}}::h5e5ed4675baeb178
at /home/runner/work/kiro-cli/kiro-cli/crates/chat-cli/src/cli/chat/mod.rs:1467
7: chat_cli::cli::chat::ChatSession::spawn::{{closure}}::h0c5de6572966d0e0
at /home/runner/work/kiro-cli/kiro-cli/crates/chat-cli/src/cli/chat/mod.rs:2053
8: chat_cli::cli::chat::ChatArgs::execute::{{closure}}::h3c13bad63f4e3687
at /home/runner/work/kiro-cli/kiro-cli/crates/chat-cli/src/cli/chat/mod.rs:675
9: chat_cli::cli::RootSubcommand::execute::{{closure}}::hd42b3bff97474072
at /home/runner/work/kiro-cli/kiro-cli/crates/chat-cli/src/cli/mod.rs:188
10: chat_cli::cli::Cli::execute::{{closure}}::h824839a24482f1a8
at /home/runner/work/kiro-cli/kiro-cli/crates/chat-cli/src/cli/mod.rs:277
11: <core::pin::Pin

as core::future::future::Future>::poll::h29588085e64c9b5d
at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/future/future.rs:133
12: tokio::runtime::park::CachedParkThread::block_on::{{closure}}::h5919de01da2ac6df
at /home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.49.0/src/runtime/park.rs:284
13: tokio::task::coop::with_budget::hd6493910b7f5b253
at /home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.49.0/src/task/coop/mod.rs:167
14: tokio::task::coop::budget::h522ef2b80041cc09
at /home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.49.0/src/task/coop/mod.rs:133
15: tokio::runtime::park::CachedParkThread::block_on::h0a401700c1a3a74d
at /home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.49.0/src/runtime/park.rs:284
16: tokio::runtime::context::blocking::BlockingRegionGuard::block_on::h63e084780701b6d2
at /home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.49.0/src/runtime/context/blocking.rs:66
17: tokio::runtime::scheduler::multi_thread::MultiThread::block_on::{{closure}}::hcf66d6efcb1a71d2
at /home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.49.0/src/runtime/scheduler/multi_thread/mod.rs:89
18: tokio::runtime::context::runtime::enter_runtime::hfa8eee1982390c1e
at /home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.49.0/src/runtime/context/runtime.rs:65
19: tokio::runtime::scheduler::multi_thread::MultiThread::block_on::h58714b760c38a952
at /home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.49.0/src/runtime/scheduler/multi_thread/mod.rs:88
20: tokio::runtime::runtime::Runtime::block_on_inner::h9050f5f7e4fe5cbc
at /home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.49.0/src/runtime/runtime.rs:370
21: tokio::runtime::runtime::Runtime::block_on::he43afcf6c4775399
at /home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.49.0/src/runtime/runtime.rs:340
22: chat_cli::main::h5f95ac90728d9b2e
at /home/runner/work/kiro-cli/kiro-cli/crates/chat-cli/src/main.rs:43
23: core::ops::function::FnOnce::call_once::h523771a5db2ce5c4
at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/ops/function.rs:250
24: std::sys::backtrace::__rust_begin_short_backtrace::h8c53fa2a4470db74
at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/std/src/sys/backtrace.rs:158
13 frames hidden

Run with COLORBT_SHOW_HIDDEN=1 environment variable to disable frame filtering.
Run with RUST_BACKTRACE=full to include source snippets.
`

I think it was tracked down to some extra args with the Prometheus MCP Server setting in my mcp.json file but I'm still seeing issues when starting up:

Model: auto (/model to change) | Plan: KIRO PRO (/usage for more detail)

57% > oracle linux 9 on i-04b4bxxxxxxxxxxx

The context window has overflowed, summarizing the history...

Conversation too short to compact.

123% >

Linux 6.6.87.2-microsoft-standard-WSL2 - Ubuntu 24.04.4 LTS

[q-details]
version = "1.26.2"
hash = "a8687141fdf1e599719c4da99f88f338aba93537"
date = "2026-02-18T03:14:21.951683Z (2d ago)"
variant = "minimal"

[system-info]
chip = "Intel(R) Core(TM) Ultra 7 155H"
total-cores = 11
memory = "15.35 GB"

[system-info.os.linux]
kernel_version = "6.6.87.2-microsoft-standard-WSL2"
id = "ubuntu"
name = "Ubuntu"
pretty_name = "Ubuntu 24.04.4 LTS"
version_id = "24.04"
version = "24.04.4 LTS (Noble Numbat)"

[environment]
cwd = "/tmp"
cli-path = "/tmp"
os = "Linux"
shell-path = "/usr/bin/bash"
shell-version = "5.2.21"
install-method = "unknown"
in-wsl = true

[env-vars]
DISPLAY = ":0"
PATH = "/home/USER/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/lib/wsl/lib:/mnt/c/Python314/Scripts/:/mnt/c/Python314/:/mnt/c/Program Files/Eclipse Adoptium/jdk-17.0.15.6-hotspot/bin:/mnt/c/WINDOWS/system32:/mnt/c/WINDOWS:/mnt/c/WINDOWS/System32/Wbem:/mnt/c/WINDOWS/System32/WindowsPowerShell/v1.0/:/mnt/c/WINDOWS/System32/OpenSSH/:/mnt/c/Program Files/dotnet/:/mnt/c/Program Files/PuTTY/:/mnt/c/Program Files/Git/cmd:/mnt/c/Program Files (x86)/NVIDIA Corporation/PhysX/Common:/mnt/c/Program Files/Amazon/AWSCLIV2/:/mnt/c/Program Files/nodejs/:/mnt/c/ProgramData/chocolatey/bin:/mnt/c/Program Files/Cloudflare/Cloudflare WARP/:/mnt/c/Users/USER/.local/bin:/mnt/c/WINDOWS/system32/config/systemprofile/AppData/Local/Microsoft/WindowsApps:/mnt/c/Users/USER/AppData/Local/Programs/Microsoft VS Code/bin:/mnt/c/Program Files/Lens/resources/cli/bin:/mnt/c/Users/USER/AppData/Roaming/npm:/snap/bin:/home/USER/.local/bin:/usr/local/go/bin"
QTERM_SESSION_ID = "de07092a61aa4bd49f0223c5924d15b3"
Q_SET_PARENT_CHECK = "1"
Q_TERM = "1.26.2"
SHELL = "/bin/bash"
TERM = "xterm-256color"