UI Page "render_gadget_priority_incidents" causes performance degradation on IE11 if added to a homepage

If the base system UI Page "render_gadget_priority_incidents" is added to a homepage and several  records are being returned within that gadget, IE11 exhibits huge performance degradation that causes the browser to freeze. Other browsers such as Chrome don't have any issue.

1. Ensure that UI16 is active.

   For more information, see the product documentation topic Activate UI16.

2. Navigate to System > UI Pages and select the base system UI Page render_gadget_priority_incidents.

3. Verify that the query is:

   var inc = new GlideRecord('incident');
    inc.addActiveQuery();
    inc.addQuery('priority',1);
    inc.setCategory('homepage');
    inc.query();

4. Create approximately 4,000 incident records that meet that criteria.

   You can run something like the following code in Scripts - Background:

   for (var i =0; i<4000;i++) {
   var rec = new GlideRecord('incident');
   rec.initialize();
   rec.short_description = 'Test' +i;
   rec.priority = "1";
   rec.insert();
   }

5. After that code finishes running, navigate to Incident > All and confirm that 4,000 records are in the incident table where priority = 1 and active = true.

6. Add the UI page to a homepage (for example, Self Service).

   1. Navigate to Self Service > Homepage.
   2. Click the + icon and then click Add content.
   3. Choose Gadgets and then choose Priority 1 Incidents.
   4. Click an Add Here location to add the gadget to the page.

7. On IE11, view this homepage with the added gadget.

   Note the performance degradation, which will eventually render the browser unusable as it freezes the page and make it unresponsive.

Use one of the following workarounds:

• Remove the Priority 1 Incidents Gadget from the homepage.
• Modify the query in the render_gadget_priority_incidents UI Page to include fewer records.