NullPointerException on clicking Reload toolbar button of Payara plugin

When user installs Payara Server / Micro plugin [1] and then clicks Reload button in main NetBeans toolbar, IDE throws java.lang.NullPointerException. See attached npe_payra.txt file.

[1] http://plugins.netbeans.org/plugin/72263

Steps to reproduce:

1. Download Payara Server / Micro plugin [1] and unzip the NBM files.
2. Install it into Apache NetBeans IDE 11.0 via Tools > Plugins > Downloaded > Add Plugins...
3. Click Reload button in main toolbar or press Ctrl+Shift+A

Expected: Payara reloads the server configuration and status.

Actual: NPE exception is thrown and nothing happens.