LiteLLM / LiteLLM
LiteLLM SMTP Configuration Crash - Nonce Length Validation Error
Fix LiteLLM crashing with nacl.exceptions.ValueError nonce must be exactly 24 bytes when configuring SMTP Includes evidence for LiteLLM troubleshooting demand.
- Category
- LiteLLM
- Error signature
nacl.exceptions.ValueError: The nonce must be exactly 24 bytes long- Quick fix
- Compare the failing environment with a known working setup, then change one configuration value at a time.
- Updated
What this error means
nacl.exceptions.ValueError: The nonce must be exactly 24 bytes long is a LiteLLM failure pattern reported for developers trying to fix litellm crashing with nacl.exceptions.valueerror nonce must be exactly 24 bytes when configuring smtp. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.
Why this happens
Reported 2026-04-07 with 10 comments. Configuring SMTP through admin UI crashes LiteLLM. Post-crash: ‘Error decrypting value for key: SMTP_SENDER_EMAIL, Incorrect padding’. Encrypts/decrypts config values are corrupted.
Common causes
- Configuring SMTP through LiteLLM admin UI triggers a crash. The nacl encryption library throws ValueError about nonce length. After restart, master key encryption is corrupted with ‘Incorrect padding’ errors. Users lose access to encrypted config values.
- Reported 2026-04-07 with 10 comments. Configuring SMTP through admin UI crashes LiteLLM. Post-crash: ‘Error decrypting value for key: SMTP_SENDER_EMAIL, Incorrect padding’. Encrypts/decrypts config values are corrupted.
Quick fixes
- Confirm the exact error signature matches
nacl.exceptions.ValueError: The nonce must be exactly 24 bytes long. - Check the LiteLLM account, local tool state, and provider configuration involved in the failing workflow.
- Compare the failing environment with a known working setup, then change one configuration value at a time.
Platform/tool-specific checks
- Verify the command, editor, extension, or API client that produced the error.
- Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
- Avoid deleting credentials, local model data, or project settings until the failing scope is clear.
Step-by-step troubleshooting
- Capture the exact error message and the command, editor action, or request that triggered it.
- Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
- Review the source evidence below and compare it with your environment.
- Apply one change at a time and rerun the smallest failing action.
- Keep the working fix documented for the team or deployment environment.
How to prevent it
- Keep provider/tool configuration documented.
- Record non-secret diagnostics such as tool version, provider name, model name, and command path.
- Add a lightweight check before CI or production workflows depend on the tool.
Sources checked
Evidence note: Reported 2026-04-07 with 10 comments. Configuring SMTP through admin UI crashes LiteLLM. Post-crash: ‘Error decrypting value for key: SMTP_SENDER_EMAIL, Incorrect padding’. Encrypts/decrypts config values are corrupted.
Related errors
- LiteLLM SMTP configuration crash
- LiteLLM nacl nonce ValueError
- LiteLLM master_key encryption corrupted after crash
FAQ
What should I check first?
Start with the exact nacl.exceptions.ValueError: The nonce must be exactly 24 bytes long text and the smallest action that reproduces it.
Can I ignore this error?
No. Treat it as a failed LiteLLM workflow until the root cause is understood.
Is this guaranteed to have one fix?
No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.
How do I know the fix worked?
Rerun the same command, editor action, or request. The fix is working when that action completes without nacl.exceptions.ValueError: The nonce must be exactly 24 bytes long.