# Troubleshooting & FAQ (/docs/products/ussd-flows/troubleshooting) ## Common Issues ### "Invalid JSON" in the Editor The flow has a JSON mistake, such as a missing comma or bracket, or it breaks a flow rule, such as a missing field or a misspelt one. Hover over each red line to see what's wrong. Common causes: - A component without a `type`. - A `type` that isn't one of the six page types: `prompt`, `menu`, `display`, `dynamic`, `template` or `side_effect`. - A misspelt field, such as `lable` for `label`. If the message mentions "unevaluated properties", a field isn't allowed on that page type. Check the [Flow Definition](/docs/products/ussd-flows/developers/flow-definition). ### The Draft Isn't Saving The editor doesn't save while the status reads "Invalid JSON". Fix the red lines first. If it reads "Unsaved", the editor saves 5 seconds after you stop typing, or press Ctrl+S (Cmd+S on Mac). If you're looking at **Published**, switch to **Draft**: the live version is read-only. ### Publish Is Greyed Out Hover over **Publish** to see why. The messages are listed in [Editing & Publishing](/docs/products/ussd-flows/editing-and-publishing#publishing). ### "Publish Draft" Is Missing on the Flow's Page It only shows when there is a saved draft. Publishing clears the draft, so the button comes back after your next saved change. ### "Action Required" in the Security Section The flow calls your server but has no public key, so you can't publish it. Add a key as shown in [Flow Security](/docs/products/ussd-flows/security). ### A Variable Shows Nothing **$(page.\*.value) is empty** - The page id doesn't match any `id` in your flow. Check the spelling and capitals. - The caller hasn't reached that page yet. You can only use answers from pages they've already passed. - The caller skipped that page because the flow jumped past it. **$(session.\*) is empty** Only these names work: `id`, `network_name`, `network_provider_name`, `subscriber_id` and `subscriber_msisdn`. Any other name is empty. **$(data.\*) is empty** This data comes from your server's reply to an exchange or a dynamic page. It is empty if that call hasn't happened yet, or if the reply didn't include the field. ### A Menu Shows No Options For a fixed list, `items` must hold 1 to 16 entries, each with a `value` and a `label`. For a list from your server, such as `"$(data.districts)"`, the data must be a list of `{ value, label }` entries by the time the menu shows. If your server hasn't sent it yet, the menu is empty. ### Callers Keep Getting "Invalid Input" The prompt's rules may be too strict. - For text, check `min_length`, `max_length` and `pattern`. Try the pattern with real answers. - For numbers, check `min_value` and `max_value`. - Set `max_invalid_input_attempts` to about 3, so one typo doesn't end the session. ### My Server Isn't Called Check that the page has an `on_done` with `"action": "exchange"` and a full `url` that can be reached over the internet. Without it, the flow moves to the next page and doesn't call your server. ### The Session Ends With an Error Your server must reply with HTTP 200 within 10 seconds, with an encrypted reply. Any failure ends the caller's session with an error. See [Security Troubleshooting](/docs/products/ussd-flows/developers/security/troubleshooting) for reply problems. *** ## Frequently Asked Questions ### Codes **Can two flows share a code?** No. Each flow has its own code and, if you ask for one, its own short code. **Can I choose my own code or short code?** No for the code: Monime picks it when you create the flow. For a short code, email [Monime support](mailto:support@monime.io). See [Codes and Short Codes](/docs/products/ussd-flows#codes-and-short-codes). ### Editing and Publishing **What happens if I close the editor without saving?** Edits from the last 5 seconds may be lost, and anything with "Invalid JSON" is never saved. Press Ctrl+S (Cmd+S on Mac) before you close. **Can I edit the live version directly?** No. Edit the draft, save it and publish. **Can I go back to an earlier version?** Not from the dashboard. Before a big change, copy the live flow as shown in [Editing & Publishing](/docs/products/ussd-flows/editing-and-publishing#going-back-to-an-earlier-version). To go back, paste it in and publish. **How fast does publishing work?** New sessions get the new version straight away. ### Screens **How long can a label be?** Phones show at most 130 characters of a label, after variables are filled in, and 64 for a menu item. The rest is cut off, so keep screens short. **How many options can a menu have?** 1 to 16. For more, split them across two menus. **Can I use bold or other formatting?** No. USSD screens are plain text. Use `\n` for a new line. ### Building Flows **Can the next screen depend on the caller's answer?** Yes. Use `on_done.next_page` to jump to another page. It can be an expression that picks the page from the answer. Your server can also decide, through an exchange or a dynamic page. See the [Flow Definition](/docs/products/ussd-flows/developers/flow-definition). **Should I use one flow or many?** One flow per service. See [Naming and Organising Flows](/docs/products/ussd-flows/managing-flows#naming-and-organising-flows). **Can I delete a flow?** No. Disable it instead. See [Managing Flows](/docs/products/ussd-flows/managing-flows#disabling-and-enabling-a-flow). ## Contacting Support If you're still stuck, especially if a published flow can't be reached, email [Monime support](mailto:support@monime.io) with: - the flow ID and code - the flow JSON, if it matters - the error message - the steps that cause the problem