If you are seeing a Go Back button with no error message, then I believe the file_inclusion_not_permitted or with_a_few_exceptions_function_calls_are_not_permitted error is being thrown. VaultWiki doesn't attempt these things in its templates, so this may be another modification you have installed.
Please post a list of your installed modifications and I will look into this. It is also possible if the mod is no longer enabled, or is no longer installed, and you still have templates that made use of function calls or file inclusions, so keep that in mind as well.