Troubleshooting
😞 Unable to send message
1. The customer sent a message 24 hours ago or a prompt such as This message is sent outside of allowed window appears
Due to Facebook Messenger's privacy policies, if24 hours pass without a reply, the Page cannot send messages to this user.
This policy is designed to protect customers from unsolicited messages and spam. If a customer contacts you, your support team will be able to send messages within the next 24 hours. If you send a message after 25 hours, your message will be rejected by Facebook.If the user sends a new message, you will be able to contact this customer again.
2. The authorized Facebook user's password has been changed
If you change your password, you need to reconnect FIRST LINE and Facebook by following the steps above.
3. The authorized Facebook user's account has two-factor authentication enabled
If you enable two-factor authentication after authorization, you need to reconnect FIRST LINE and Facebook by following the steps above.
4. Error message appears
#190
Error validating access token or Error validating access token: The session has been invalidated because the user changed their password or Facebook has changed the session for security reasons
When you see this error message, it means your authorization has expired, preventing access to data. This often happens because the authorized person changed the Instagram or Facebook password linked to the system, or because the conversation was invalidated for security reasons. If Facebook detects unusual activity, it may take the above action.
Please ask the original authorized person or another fan page member with the same administrative privileges to reauthorize the system according to the documentation.
#551
This user is currently unavailable; this user cannot receive your messages right now
This may mean that the user has blocked your fan page, or that the user has deactivated their account.
#100
Upload attachment failure.
Meta does not accept this file, possibly for the following reasons:
1. Corrupted file: Please check whether the file is complete and undamaged.
2. Unsupported file extension: Make sure you use common formats such as jpeg, jpg, and png.
3. File extension does not match the actual file type: if a jpg file has been renamed to png, please use the correct file format.
In a few cases, this is due to an issue on Meta's side (this has happened before). Please try again later.
Please try common formats such as JPEG / JPG / PNG. Make sure your file format is correct and try uploading again.
#10
This message was sent outside the allowed time window This message is sent outside of allowed window
This means the Facebook allowed reply window has been exceeded, also known as the "24+1" policy. This means that after Facebook sends a message to the user, if the user does not reply within 24 hours, you can only proactively send one more message. If the user still does not reply after that message, you can no longer send broadcasts to this user. This is a Facebook usage restriction designed to ensure compliance and provide a good user experience.
#-1
Unexpected internal error
This means Facebook encountered an unexpected error, and you are advised to try your request again later.
#-2
Timeout while uploading message attachment; please try again later
This means Facebook encountered an unexpected error, and you are advised to try your request again later.
💬 No message received
1. Page-to-page messaging
When a Page sends a message to another Page, META does not currently provide a corresponding event, so it is normal for the system not to receive the message. This means that when one Page tries to send a message to another Page, the system will not trigger any related event to process those messages.
2. Facebook native automated flow
When a customer message is triggered by a Facebook automated flow (such as collecting leads through an ad post), these messages will be taken over by Facebook first, so they cannot directly enter FIRST LINE.
It is recommended to check the source of bot messages in the customer conversation:
Check whether the message was sent by the FIRST LINE system: If the message was not sent by FIRST LINE, it is very likely being handled by Facebook automation or another third-party service.
Wait for the flow to end: Once the customer completes Facebook's automated flow, subsequent messages may then be received by the third-party system.
3. Using other third-party systems or services at the same time
If you use multiple third-party systems or services, make sure only one service is receiving the Webhook at a time to avoid messages being delivered to other systems and causing FIRST LINE to miss messages.
If you are using multiple third-party services to receive messages at the same time, please remove the extra services or manage them according to the following settings:
Manage Page: Switch to the Page identity, click the avatar in the top right, choose "Settings & privacy", and then click "Settings".
Page settings: In the left sidebar, select "Page settings", then click "Advanced messaging".
App settings: On the right, find the "View" button and click it. Then find "App settings - Handover Protocol" and, under the setting on the right side of "Messenger recipient", choose "FIRST LINE".
4. Meta missed the Webhook message
Since FIRST LINE integrated the Facebook Messenger channel, we have found that in very rare cases, Meta fails to properly deliver messages or information to third-party services. This means that when a customer sends a message, Meta fails to notify other services of that message, or the message is missing some field information, causing the system to be unable to display it.
According tothe official developer forum and cross-checking records from issues reported by other users and the internal team responsible, we found that this is a normal occurrence. At different points in time, some users in the community have raised this issue, but unfortunately, Meta has not provided much explanation for it. Sometimes they only said that a fix had been made.
For this situation, our team members are actively strengthening records of information from Meta to prepare for possible future anomalies and changes on the official side. If you encounter this situation, please let us know the timing of the customer's message and other information, and we will help you confirm whether it matches this case.
Other
1. Customer nickname is shown as Guest
When a customer comes in through Facebook or messages for the first time, the system will try to obtain the customer's information, including nickname. However, in some cases, due to Facebook's limitations, complete information may not be available, resulting in the user being shown as a guest. These situations include:
The user started a conversation through the checkbox plugin and did not reply to the message on Messenger.
The user interacted with a Messenger message ad before replying to the message on Messenger.
Profile information retrieval is not supported for Messenger accounts created with a phone number.
...and other Facebook limitations that may affect the collection of user information. However, the system will still try to provide as much information as possible where available to help deliver more personalized service.
2. Incoming chats with names composed of Guest plus numbers
If some customers on your fan page are shown as "Guest" followed by a four-digit number, such as Guest 6521 or Guest 9527, this means you have enabled the fan page message "Guest mode". In guest mode, conversations are time-limited, and when the customer clicks "End chat", the conversation box will close and the agent will no longer be able to reply to messages.
3. Name shown as UNKNOWN
If the customer name is shown as UNKNOWN / Unknown, it means FIRST LINE has received an event from Facebook, but when creating the customer record, it could not obtain the user's name and profile picture from Meta Messenger profile information, so UNKNOWN is temporarily used as the display name.
Possible situations include:
Meta returns that no matching Messenger user was found, for example "No matching user found".
The user's account currently cannot provide profile information, such as when the account is deactivated, the user has blocked the fan page, or Meta privacy and permission restrictions apply.
The identifier IDs used by some Facebook interaction events may not be directly available through the Messenger profile interface to obtain user data. For example, events such as post interactions may use identifier IDs from a different scope.
Meta temporarily did not return complete user information, or a profile lookup encountered an abnormality.
4. The staff member who linked FIRST LINE with the Facebook Page has left the company
Suppose the original administrator Kevin linked FIRST LINE with your Facebook fan page. If Kevin has left the company, you can remove Kevin's administrator privileges from the Facebook fan page.
When the administrator privileges are removed, the connection between FIRST LINE and Messenger will become invalid because Kevin's access token is being used.
In this case, what you need to do is reauthorize FIRST LINE and Messenger by following the steps above.
5. Message tag types
Live customer support Human Agent
Within 7 days after receiving the user's message, a live agent replies to the user's message. This feature is intended for cases where the user's issue cannot be resolved during the standard messaging window, such as when a business is closed on weekends or when resolving the issue takes more than 24 hours.
Replying to issues that take more than 24 hours to resolve, or messages during weekends and holidays when the business is open.
Event update Confirmed_Event_Updat
Confirm a user's booked event, remind the user of an upcoming event, and notify the user of schedule changes.
Event notifications or booking confirmations, event or appointment reminders, event or appointment cancellations, or status changes.
Order update Post_Purchase_Update
Used to confirm payment status, send invoices or receipts, shipping status, and handle unexpected situations.
Shipping status notifications, purchase shipping notifications, order-related changes (such as card payment issues, order cancellations, etc.).
Account update notificationAccount_Update
Notifications include changes to application information, alerts for suspicious activity, changes in job posting status, and more.
Account activity notifications, user profile change notifications.
Advanced exclusion
Go to the linked Facebook fan page and click "Settings", then go to "Advanced messaging".
Click the application settings button linked to "FIRST LINE" to remove it.
After removal is complete, reauthorize the connection between the Facebook fan page or Instagram business account and the integration.
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