A typo has been identified in the official Mattermost media type template script: the attachment property fallback is misspelled as fallbac inside the createMessage function.

Impact

Because the attachment does not match Mattermost API expectations, notifications can:

• lose their plain-text summary (fallback text), or
• fail to display correctly in mobile notifications and desktop popups.

Steps to Reproduce

1. Open the official Mattermost media type template script.
2. Locate the createMessage function.
3. Find the line where the attachment is built and observe the typo:

   fallbac: params.alert_subject
   

Verification

Confirmed the typo exists in the official repository branches:

• release/6.0
• release/6.4
• release/7.0
• master

Suggested Fix

Update the property name from fallbac to fallback (around line ~354 in the template script).

Patch (Minimal Change)

Unable to find source-code formatter for language: diff. Available languages are: actionscript, ada, applescript, bash, c, c#, c++, cpp, css, erlang, go, groovy, haskell, html, java, javascript, js, json, lua, none, nyan, objc, perl, php, python, r, rainbow, ruby, scala, sh, sql, swift, visualbasic, xml, yaml- fallbac: params.alert_subject,
+ fallback: params.alert_subject,

Expected Result

Mattermost notifications include a plain-text fallback summary and render consistently on mobile devices and desktop popups.

Actual Result

Fallback summary is missing or notifications render inconsistently due to the incorrect property name (fallbac).