Description of the Issue

After you use the feature open folder as workspace in NPP, then when you create a new folder from Windows Explorer, the new folder doesn't show up in the tree view under NPP "Folder as Workspace".

Steps to Reproduce the Issue

1. View --> Folder as Workspace
2. Drag and drop a folder to the workspace panel
3. Use File Explorer to create a new folder under the main folder of the workspace created in NPP
4. Switch to NPP, and the new folder is not visible

Expected Behavior

The new folder must show

Actual Behavior

The new folder didn't show

Debug Information

Notepad++ v7.5.6 (32-bit)
Build time : Mar 19 2018 - 00:26:59
Path : C:\Program Files (x86)\Notepad++\notepad++.exe
Admin mode : OFF
Local Conf mode : OFF
OS : Windows 7 (64-bit)
Plugins : ComparePlugin.dll CustomizeToolbar.dll DSpellCheck.dll JSLintNpp.dll JsMapParser.NppPlugin.dll JSMinNPP.dll mimeTools.dll NppConverter.dll NppExport.dll NppFTP.dll NPPJSONViewer-win32.dll NppTextFX.dll PluginManager.dll SourceCookifier.dll Tidy2.dll XMLTools.dll