Can you verify that you have /dbtech/vbquiz/actions/admin/typeedit.php on your server?
If it is there then click click on the Modify link and select to open in a new window. Copy and paste that link here so I can see where it's trying to direct you.
The name of the file used for quizzes. The default is vbquiz.php
I have rename vbquiz.php but not the file in the admin.
After rename also this file, problem is solved.
Maybe it is a good idea to wrote it in the manuel that there must be two files renamed.