Email Extension plugin failing to send emails with the content of Jenkins environment variables after the Jenkins update from 2.263.3 LTS to 2.277.3. Following how my configuration looks like
 

Editable email configuration project level(picture attached):

Project Reply-To List: $DEFAULT_REPLYTO

Content Type: HTML

Default Subject: $DEFAULT_SUBJECT which is $PROJECT_NAME - Build # $BUILD_NUMBER - $BUILD_STATUS!

Default Content : ${SCRIPT, template="email-template.groovy"}

After successful build I am getting email like below (picture attached).

I am not sure why I am getting email with variable names but not with its content.It was working perfectly before Jenkins upgrade. Any help appreciated.