If you experience an error while updating a form using Developer Toolbox File Upload similar to this:

tNG_multipleUpdate error. An error occurred while updating the records. (MUPD_ERROR)

Here is a possible fix:

Open the following file in the includes folder

\includes\tng\triggers\tNG_FileUpload.class.asp


At line 155 you should see:

If Not tNG_isFileInsideBaseFolder(folder, saveFileName) Then

Change this line to read

If Not tNG_isFileInsideBaseFolder(folder, saveFileName) AND saveFileName<>"" Then


This has fixxed the problem several times for me

Credit goes to KK Law and Nathan Green for the original find on the adobe forum here