I am running DNN 4.0.8 and File Manager stopped working.  I can see folders and files in Portal Root but not inside any other folders.  When I double click on a folder in the tree I get the following error:

dnn.controls.controls[m_sDNNTreeID].selTreeNode is null

from the getSelectedTreeNode() in FileManager.ascx.

Here are some other related lines of code:

m_sUCPrefixID = dnn.getVar('UCPrefixID');
m_sDNNTreeID = m_sUCPrefixID + 'DNNTree';

But then I am stuck, I don't know where getVar gets data for the key UCPrefixID.

Synchronize files is not working either. 

Any help will be greatly appreciated.

I don't see any unusual characters or duplicate filenames.  The only things that seem unusual are that my folder #1, which looks like my portals/_default folder and folder #16, which looks like portals/0 folder do not have anything listed in the folder path field.  Likewise, the files that are in folders #1 and #16 do not have folder names.

I also noticed that the following files in portals/_default (as viewed via ftp) do not appear in the dnn_files table: 4.06.00.config, 4.07.00.config, 4.08.00.config, and subhost.aspx

Any ideas?  Thank you for your help.

I just tried your suggestion, no change.

The problem has to do with the variable m_usUCPrefixID.  I am having problems adding a folder, synchronizing, etc, anything in FileManager having to do with locating a folder or file path. In the statement below, where is the key "UCPrefixID" stored? 

m_sUCPrefixID = dnn.getVar('UCPrefixID');