Problems with Raven add-on since upgrading to 1.9

When I submit a form using Raven, I get the following error in the admin system when I try and view the forms page:

14. RuntimeException
…/­_app/­vendor/­Symfony/­Component/­Finder/­SplFileInfo.php72

In formsets/contact.yaml

submission_save_path: _forms/contact/ 

and in raven.yaml

submission_save_path: _forms/

if I comment these out, sometimes the forms page will load in the admin.

A new submission gets created but it's always completely blank.

Looking forward to hearing from you.

Many thanks Kristina