Issue Summary

After updating from Jira 7.13.1 to 8.0.2 the "Jira Issues Calendar" gadget stopped working on Confluence side.

Updated the Calendar plugin and the iCal plugin to 5.0.0 and 1.5.0 but the issue still remains.

The gadget does work in Jira but not in Confluence.
In Jira, the _MODULE_ID_ seems to get replaced by a number.
This does not happen when the gadget is added to a Confluence page.

Expected Results

The gadget should work as expected.

Actual Results

In the JS console:

Uncaught ReferenceError: __MODULE_ID__ is not defined
at Object.ajaxOptions (ifr?container=atlassian&mid=1652235632640&country=GB&lang=en&view=default&view-params={"writable"%3A"false"}&st=atlassian%3AUesc%2Fa%2BQ2qVOxw8%2FywsU01ejCk5NZXu54mIp8sIol0d2YHE6pin5cFBgWEJAgqHRyGh7WyhZD7XFyodeZz8qSmDIBMXR5wpRKaDzl6vAaudt%2F%2F9hwXUztOTJCeEUmkD4lI6m7Wm3ygp7b4T6jsKUhOVwlDDvThGxZXSpLW9gAgOpoDi3vhvlojj1jApavEiZ05QzeBNS1XBYuKxfIXcNpmLrkusAI0hfr%2FbUrvB2NtmQWCdWMFlWQDoxbu0oqUZ7LJXz81YLuxIYszRQy8px17zBfE8U4PBH9TRfxxY%2FPi0eOEad9457szRvxD30n%2B16oGGMNgq31Zdv%2BWXEe0Z6NDWyc87EOgQ3jQL1jv5Qb%2Fpn9PH%2BTdMEwnfcFt1xj3%2BymOD%2FXw%3D%3D&up_isConfigured=true&up_projectOrFilterId=filter-20532&up_dateFieldName=customfield_11426&up_displayVersions=false&up_numOfIssueIcons=10000&up_refresh=15&url=https%3A%2F%2Fjira%2Frest%2Fgadgets%2F1.0%2Fg%2Fcom.atlassian.jira.ext.calendar%3Aissuescalendar-gadget%2Ftemplates%2Fplugins%2Fjira%2Fportlets%2Fcalendar%2Fgadget%2Fcalendar-gadget.xml&libs=auth-refresh:516)
at Object.ajaxOptions (com.atlassian.gadgets.publisher:ajs-gadgets-lite.js:33)
at Object.<anonymous> (com.atlassian.gadgets.publisher:ajs-gadgets-lite.js:6)
at Function.each (com.atlassian.plugins.jquery:jquery.js:17)
at c.fn.init.each (com.atlassian.plugins.jquery:jquery.js:17)
at Object.getDescriptorData (com.atlassian.gadgets.publisher:ajs-gadgets-lite.js:6)
at Object.build (com.atlassian.gadgets.publisher:ajs-gadgets-lite.js:6)
at Object.showView (com.atlassian.gadgets.publisher:ajs-gadgets-lite.js:33)
at com.atlassian.gadgets.publisher:ajs-gadgets-lite.js:36

Workaround

Note that this was only tested locally by the developer checking this error (no guarantees)

As a workaround I'd recommend to remove old gadgets jars and replace them with 4.3.7 version (I've tested it locally and it worked, but no guarantees here as it was quick and brutal test).

• stop confluence
• go to atlassian-confluence-6.15.7/confluence/WEB-INF/atlassian-bundled-plugins
• remove gadgets related jars
  atlassian-gadgets-api-4.3.2.1.jar
  atlassian-gadgets-directory-plugin-4.3.2.1.jar
  atlassian-gadgets-embedded-plugin-4.3.2.1.jar
  atlassian-gadgets-oauth-service-provider-plugin-4.3.2.1.jar
  atlassian-gadgets-opensocial-plugin-4.3.2.1.jar
  atlassian-gadgets-publisher-plugin-4.3.2.1.jar
  atlassian-gadgets-shared-4.3.2.1.jar
  atlassian-gadgets-spi-4.3.2.1.jar
• copy updated jars
  atlassian-gadgets-api-4.3.7.jar
  atlassian-gadgets-directory-plugin-4.3.7.jar
  atlassian-gadgets-embedded-plugin-4.3.7.jar
  atlassian-gadgets-oauth-service-provider-plugin-4.3.7.jar
  atlassian-gadgets-opensocial-plugin-4.3.7.jar
  atlassian-gadgets-publisher-plugin-4.3.7.jar
  atlassian-gadgets-shared-4.3.7.jar
  atlassian-gadgets-spi-4.3.7.jar
• start confluence, see if all the plugins are running and if calendar gadget is working correctly

Steps to reproduce:

• Start Jira 8.3.1 (or later) and install Jira Issues Calendar latest version: https://marketplace.atlassian.com/apps/293/jira-calendar-plugin?hosting=server&tab=support
• Restart Jira server
• Create a project, add tickets and input "DUE DATE" for Jira ticket
• Copy the Jira Issues Calendar gadget spec: XML file 
• Start confluence 6.15.9 (latest 6.15.x)
• Go to confluence admin -> external gadget: add url Jira Issues Calendar gadget spec above
• Create application link Confluence < - > Jira
• Create a page: In editor to insert gadget (search for Jira Issue Calendar), and Input Project Name into the filter
• Saving the gadget config, then insert the gadget to the page
• Go to view page and see result (open browser console)
• Upgrade confluence to 7.0.1 to see the page again.