Short code and WPForm not working in WP

Hi, I am using Catch Bells free theme in Wordpress.org. I have been using the theme for nearly 1 year. I have tried to change the post templet recently. All the short code and WPForm are working well on the day of the change. However, all the short code and form are not working the day after on all pages and posts, includes homepage. Then, I deleted all short code and form from the templet, and added to the content area, now they are working. But the WPForm in the footer is still not working. What can I do to fix the issue in case it happens again. Thank you.