How to Fix “Template Error” in SendGrid (2026 Guide)

The Short Answer

To fix the “Template Error” in SendGrid, advanced users can directly check their Handlebars syntax for any missing or mismatched tags, and ensure that their template is properly configured. By verifying the syntax and configuration, users can resolve the issue and successfully send emails via the Email API.

Why This Error Happens

  • Reason 1: The most common cause of the “Template Error” is incorrect or incomplete Handlebars syntax in the email template, such as missing or mismatched {{ }} tags. This can occur when using conditional statements, loops, or variables in the template.
  • Reason 2: An edge case cause of this error is when the template is referencing a non-existent or null variable, causing the Handlebars engine to throw an error. This can happen when using custom variables or data sources in the template.
  • Impact: The “Template Error” affects the Email API, preventing emails from being sent and resulting in failed delivery attempts. This can lead to delayed or lost communications with customers, potentially impacting business operations and reputation.

Step-by-Step Solutions

Method 1: The Quick Fix

  1. Go to Settings > Template Settings > Handlebars Configuration
  2. Toggle Strict Mode to Off, which will allow the template to render even with minor syntax errors
  3. Refresh the page and reattempt to send the email via the Email API

Method 2: The Command Line/Advanced Fix

For advanced users, you can use the SendGrid API to update the template and fix the Handlebars syntax. Use the following code snippet to update the template:

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curl -X PATCH \
  https://api.sendgrid.com/v3/templates/{template_id} \
  -H 'Authorization: Bearer {api_key}' \
  -H 'Content-Type: application/json' \
  -d '{
        "name": "{template_name}",
        "versions": [
          {
            "html_content": "{updated_html_content}",
            "plain_content": "{updated_plain_content}",
            "subject": "{updated_subject}",
            "handlebars": {
              "version": "4.7.7"
            }
          }
        ]
      }'

Replace {template_id}, {api_key}, {template_name}, {updated_html_content}, {updated_plain_content}, and {updated_subject} with the actual values for your template.

Prevention: How to Stop This Coming Back

To prevent the “Template Error” from occurring in the future, follow these best practices:

  • Regularly review and test your email templates for any syntax errors or issues
  • Use a version control system to track changes to your templates and roll back to previous versions if needed
  • Monitor your email delivery metrics and investigate any failed deliveries or errors
  • Consider using a template validation tool or service to catch errors before they occur

If You Can’t Fix It…

[!WARNING] If SendGrid keeps crashing due to the “Template Error” and you are unable to resolve the issue, consider switching to Mailgun which handles Handlebars syntax natively without these errors. However, be aware that this may require significant changes to your existing email infrastructure and workflows.

FAQ

Q: Will I lose data fixing this? A: No, fixing the “Template Error” should not result in any data loss. However, if you are updating your template using the API, make sure to backup your existing template data before making any changes.

Q: Is this a bug in SendGrid? A: The “Template Error” is not a bug in SendGrid, but rather a result of incorrect or incomplete Handlebars syntax in the email template. SendGrid’s Handlebars engine is based on version 4.7.7, which is a stable and widely-used version of the library. However, SendGrid has released updates and patches to improve the handling of edge cases and syntax errors, so make sure to check the version history and update your template accordingly.

📚 Continue Learning

Check out our guides on SendGrid and Template Error.