# "Error starting call" when running browser test call

**URL:** <https://community.retellai.com/t/error-starting-call-when-running-browser-test-call/3639>\
**Category:** Support Help\
**Tags:** bug\
**Created:** [September 10, 2026, 6:25pm UTC](https://community.retellai.com/t/error-starting-call-when-running-browser-test-call/3639 "2026-09-10T18:25:37Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![mussab](https://yyz2.discourse-cdn.com/flex008/user_avatar/community.retellai.com/mussab/32/2702_2.png) [@mussab](https://community.retellai.com/u/mussab)\
**Post date:** [September 10, 2026, 6:25pm UTC](https://community.retellai.com/t/error-starting-call-when-running-browser-test-call/3639/1 "2026-09-10T18:25:37Z")

</div>

1. 

> Hi, I’m having an issue starting a browser test call from my Retell AI agent.
> 
> Whenever I click “Run Test”, I immediately receive:
> 
> **Error starting call**
> 
> The agent is published, my browser microphone permission is enabled, and my account still has free-trial credit available.
> 
> I also tested different supported LLM models, but the same error occurs.
> 
> The agent-level webhook test is working successfully, so the webhook itself appears reachable.
> 
> No call/session appears in Call History after the failed attempt.
> 
> Could you please check whether there is an account, workspace, agent, or trial restriction preventing browser test calls from starting?
> 
> Thank you.

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<div class="post-metadata">

**Author:** ![mark1](https://yyz2.discourse-cdn.com/flex008/user_avatar/community.retellai.com/mark1/32/2524_2.png) [@mark1](https://community.retellai.com/u/mark1)\
**Post date:** [September 10, 2026, 6:47pm UTC](https://community.retellai.com/t/error-starting-call-when-running-browser-test-call/3639/2 "2026-09-10T18:47:35Z")

</div>

Hey @mussab

Since no call/session appears even in Call History, the failure is likely happening before the call registers — commonly caused by browser permission/domain issues or an LLM/agent configuration problem.

A few things to check :

1. **Custom LLM issues** : If using a custom LLM, **`error_llm_websocket_open`** occurs when the websocket can’t open — check your LLM server is reachable. See **[custom LLM troubleshooting](https://docs.retellai.com/integrate-llm/troubleshooting)**.

2. **Payment/trial restriction** : **`no_valid_payment`** is a known error reason when no valid payment is on file (though you mention trial credit remains) — worth double-checking billing status.

3. **Public key domain allowlist** : For web calls, **[Make a web call](https://docs.retellai.com/deploy/web-call)** FAQ notes calls can fail before starting if the public key’s allowed domains, agent ID, or mic permission aren’t correctly set — worth re-verifying the allowed domain for your test.

4. **No call in history** : This matches errors that occur before the session registers (e.g. **`error_user_not_joined`** , or an immediate rejection before call creation), rather than a mid-call disconnect.

Since the error is generic (“Error starting call”) with no call record, this needs a closer look at your specific agent config — check the browser console for the detailed error **`onError`** payload as noted in **[Make a web call](https://docs.retellai.com/deploy/web-call)**,

since that reveals the actual failure reason (domain mismatch, invalid agent ID, etc.).

Best Regards.