# Common issues

> Causes and fixes for common problems, such as a sign-in code that doesn't arrive, running out of credits, or LINE sending stopping.

This page lists common problems, grouped by what you see on the screen.

## The sign-in code doesn't arrive

- Look for an email from "mukumo" with the subject "Your sign-in code". Check your spam folder too.
- If it doesn't arrive, you can click **Send again** after 30 seconds.
- The code works once and expires after 15 minutes.
- If you see "Too many attempts. Wait a minute and try again.", wait about a minute and try again.

## The invitation email doesn't arrive or has expired

- Ask the person who invited you to send you the link directly, using **Copy invite link** in the "Pending invitations" list.
- If you see "This invitation wasn't found or has expired", ask them to invite you again (invitations expire after 7 days).
- If you see "This invitation was sent to a different email address", sign in again with the email address that was invited.

## You don't have enough credits

When you see "This month's credits are used up.", chats, calls, and read-aloud with muku stop. Actions you take on the screen keep working.

- Monthly credits reset on the 1st of every month (Japan time, JST).
- Upgrade your plan or buy more credits to keep going (**Settings** > **Plan & billing**). You can buy more credits only on a paid plan.

For details, see [Credit usage](/docs/en/muku/credits/) and [Buy more credits](/docs/en/billing/plans-and-billing/#buy-extra-credits).

## LINE messages don't send or the account stopped

When mukumo finds a problem with an account, it stops everything that sends automatically (broadcasts, scenarios, reminders, auto-replies, and more) and emails the organization's owners and admins. The reason appears at the top of the LINE management page.

| Why it stopped | How to fix it |
| --- | --- |
| Stopped automatically because the access token no longer works | Reconnect the account in **Manage accounts** |
| Stopped automatically because LINE refused a send (403) | Check the account in LINE Official Account Manager |
| Stopped automatically because this month's messages are used up | Upgrade the LINE plan, or wait until next month |
| Stopped automatically because (number) people blocked the account in the last hour | Check what was sent |

mukumo stops sending on a sudden rise in blocks only when **Stop automatic sending when alerting** in **Manage accounts** is on (it starts on).

- Sending doesn't resume on its own after you fix the cause. An owner or admin clicks **Resume**. Messages queued while sending was stopped aren't lost. They wait and start sending as soon as you resume.
- mukumo checks the account status every 30 minutes. To check right away, click **Check now**.

## You can't sign in with a passkey

- If you see "This passkey isn't registered.", sign in another way, then register your passkey again under **Account** in the settings.
- If **Use a passkey** doesn't appear on the sign-in page, your browser doesn't support passkeys. Sign in another way.
- Passkeys don't work in the browser inside LINE. Sign in with the email code.

## You lost the device with your authenticator app

When you sign in, choose **Use a backup code** and enter one of the backup codes you received when you set up the authenticator app. You have 10 backup codes, and each one works once. After you sign in, set up the **Authenticator app** again under **Account** in the settings.

## You can't call muku

- If you see "You don't have enough credits to call.", check your credits. A call uses 10 credits per minute.
- If you see "Couldn't use your microphone. Allow microphone access in your browser settings.", allow microphone access for this site in your browser settings.
- A call lasts up to 30 minutes.

## The API returns an error

| Status | Cause |
| --- | --- |
| 401 | The API key is missing or incorrect |
| 403 | Your plan doesn't include the API, or you tried to make a change with a read-only key |
| 429 | You went over the per-minute limit (60 requests per key) or the monthly limit |

You can create up to 10 API keys per organization.