KB0021 - Unable to update Dashboard Pages in PowerShell Universal 3.6.4

KB0021 - Unable to update Dashboard Pages in PowerShell Universal 3.6.4

Purpose

Due to an issue with the client-side application in PowerShell Universal 3.6.4, you may experience a problem updating page content. When clicking the Save button, a toast message would be shown that states that a 400 HTTP error had occurred. The log would state "Object Reference Not Set to an Instance of an Object". 

Solution #1

Ensure that the dashboard using the page feature is listed first in the .universal\dashboards.ps1 file. Each dashboard increments in ID and after the 9th, it will not work. 

Solution #2

Upgrade to version 3.7.0 or later of PowerShell Universal. 

Root Cause

Due to an issue in the admin console, pages wouldn't update if they were a part of a dashboard that had an ID over 9. This was due to an improperly defined Regular Expression.