Instead of do_shortcode you will need to use apply_filters if you are using the shortcode provided by MembershipWorks in your theme templates. do_shortcode won’t work with the MembershipWorks snippets codes.
You can find different shortcodes in the help section.
How to use the MembershipWorks shortcodes in PHP templates
Replace
<?php echo do_shortcode('[mw open="!calendar/r"]'); ?>By this:
<?php echo apply_filters( 'the_content',' [mw open="!calendar/r"] '); ?>And this should solve the issue of the shortcode not working. Remember that you can only use one MembershipWorks shortcode per page.