Commented Unassigned: File Browser Settings: ParentFolder Cannot be Null [7591]

CKEditor 2.0.6 on DNN 7.0.5. When attempting to modify the CKEditor File Browser Settings for a portal Page, the following error occurs.

[ArgumentNullException: Value cannot be null.
Parameter name: parentFolder]
DotNetNuke.Common.Requires.NotNull(String argName, Object argValue) +66
DotNetNuke.Services.FileSystem.FolderManager.GetFolders(IFolderInfo parentFolder) +54
WatchersNET.CKEditor.Browser.Browser.FillFolderTree(String path) +575
WatchersNET.CKEditor.Browser.Browser.Page_Load(Object sender, EventArgs e) +3231
System.Web.UI.Control.LoadRecursive() +71
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3178

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.17929
Comments: ** Comment from web user: saunan **

Yes, the issue does occur in CKEditor 2.0.7. We've also upgraded the site to DNN 7.01.01, and the CKEditor error still happens.

Another fact which may help: With Browser Root Folder and Default Upload Folder changed in File Browser Settings, the "Upload | Send to Server" process works just fine. It's the "Browse Server" function that's broken.

Here's the latest error message.

Exception Details: System.ArgumentNullException: Value cannot be null.
Parameter name: parentFolder

Stack Trace:

[ArgumentNullException: Value cannot be null.
Parameter name: parentFolder]
DotNetNuke.Services.FileSystem.FolderManager.GetFolders(IFolderInfo parentFolder) +210
WatchersNET.CKEditor.Browser.Browser.FillFolderTree(String path) +591
WatchersNET.CKEditor.Browser.Browser.Page_Load(Object sender, EventArgs e) +3176
System.Web.UI.Control.LoadRecursive() +71
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3178

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.17929