LAR importing of events with comments fails with com.thoughtworks.xstream.mapper.CannotResolveClassException

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.0 M3
• Fix Version/s: 7.0.0 M1
• Component/s: Calendar, Staging > Export/Import, ~[Archived] WCM
• Labels: None
• Story Points: 9
• Fix Priority: 5
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/18807

When importing a LAR containing calendar bookings with comments, the com.thoughtworks.xstream.mapper.CannotResolveClassException exception is thrown.

Steps to reproduce

Creating a site calendar

1. Deploy the calendar portlet; add it to a page.
2. Click in the "Current site calendars" arrow; click in "Add Calendar"
3. In the calendar configuration window, enter a name for it and check the "Enable comments" checkbox. Save the calendar.

   Creating commented event

4. Add an event in the newly created calendar.
5. Click on the event; click in "View Details".
6. Click in "Be the first." Enter a content for the comment. Click in "Reply"
7. Close the "View Details" window.

   Exporting pages

8. Go to "Admin" (at top right) and then click in "Site Administration."
9. In the "Site pages" section, click in "Export". In the new screen, click in "Export"
10. In the new screen, at the "Download" column of the table, click in the link.

    Importing the page

11. Click in "Admin", then in "Control Panel"
12. Click in "Sites." Click in "Add", then in "Blank Site"
13. Enter a name to the site. Save it.
14. In the new screen, click in "Pages", then "Site Pages"
15. Click in "Import"
16. Drag the downloaded LAR file to the dashed area (or upload it clicking in "Select File")
17. Click in "Continue", then in "Continue" again, then in "Import".

Expected results

• A "Successful" message will apear.

Actual results

• A "Failed" message appears.
• In its "Details", there is the message:

An unexpected error occurred with the publication process. Please check your portal and publishing configuration.
com.thoughtworks.xstream.mapper.CannotResolveClassException: com.liferay.portlet.messageboards.model.impl.MBMessageImpl