> ## Documentation Index
> Fetch the complete documentation index at: https://moengage.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Common Errors in SMS and  RCS Campaigns

> Troubleshoot common internal and service provider errors encountered when sending SMS and RCS campaigns through MoEngage with detailed explanations.

This article explains common errors you might see when sending SMS and RCS messages through MoEngage.

# Internal Errors

Following are a few errors that are generated by MoEngage while sending SMS & RCS messages:

| Error                                     | Description                                                                                                                                                                                                                                                                                                                                                                                                      |
| ----------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Personalization Failed                    | This error occurs when message personalization fails and no fallback message is configured. The system will not send the message to the user and generates the Personalization Failed error.                                                                                                                                                                                                                     |
| Invalid Mobile Number                     | This error appears if a user's mobile number is invalid. This includes scenarios where:   <br />- The **Mobile number** field is empty or contains placeholder values such as **None**, **N/A**, **undefined**, **null**, or **0**. <br />- The **Mobile number** contains non-numeric or Unicode characters, or is fewer than 4 digits long. <br />- The mobile number cannot be converted to the E.164 format. |
| Users removed due to Global Control Group | This error occurs when the user is part of the Global Control group, and hence, MoEngage did not send any message to the user.                                                                                                                                                                                                                                                                                   |
| Rejected because of DND                   | This error occurs when you attempt to send messages during the configured DND hours. MoEngage will not send the message to the user in such a case.                                                                                                                                                                                                                                                              |
| Not sent due to campaign level min delay  | This error occurs when the user qualifies for multiple messages from the same campaign, but the message is not sent because of the minimum delay settings between the campaign.                                                                                                                                                                                                                                  |

# Service Provider Errors

| Error          | Description                                                                              |
| -------------- | ---------------------------------------------------------------------------------------- |
| Failed to send | This error is displayed if the user ID hasn't been allowlisted on the GupShup dashboard. |