Numbered fields break the Filter Results widget

Issue Summary

The Filter Results macro is amazing to pull up JIRA information on Confluence pages, making beautiful reports of our projects.
Though, when inserting a new Filter or editing an existing one, if you have a numbered field on your JIRA project and would like to add it into the filter, it won't work.

Steps to Reproduce

1. Create a custom field on JIRA (or select an existing custom one created by Jira, like Story points), selecting the Numbered one.
2. Still on JIRA, create a filter from a project that you added the previously created custom field;
3. Go to Confluence and create a new page;
4. Call the widget with /filter;
5. Chose the filter you just created;
6. On the add fields drop-down list, find the numbered custom field you created and add it;
7. Save the display options of the widget.

Expected Results

A preview of the widget is loaded.

Actual Results

Nothing happens and you can no longer use this macro - you have to cancel and start it over.

Notes:

• As soon as you hit the Save option in the display options, some 200 requests are displayed, but with an error similar to this: SyntaxError: JSON.parse: unexpected keyword at line 1 column 1 of the JSON data
• The issue also happens when a user using Text Field (multi-line) and Select List (single choice)

Workaround

Users may use Jira issue macro to display the field.