SMS Character Counter breaks SMS Action Popup

Overview

In 5.40.1+ the new SMS Common Template includes a character counter -- This feature works great if the SMS message is constructed using a full page, but if you select a "Outbound SMS" from an individual's action menu the pop up version of the SMS composer breaks.

Reproduction steps

1. Open Individual
2. In Action Menu -> Select "Outbound SMS"
3. Composer loads, but Templates, Tokens, Contact Name, and Counter are blank.
4. Error in console is "Uncaught ReferenceError: SmsCounter is not defined"

Current behaviour

SMS Composer pop up is blank with error

Expected behaviour

SMS Composer pop up should function the same way as a single page composer.

Environment information

Seen in Wordpress and Drupal with CiviCRM 5.40.2

Comments

It appears the changes from this issue created this error - #1711 (closed)