resources and default bucket

Just installed latest Perch version (nb NOT runway). No content has been uploaded yet. A logo image has been uploaded via admin and I can see that in the resources directory.

However when I click on organis 'assets' in admin I get an error 500 and can see nothing.

Do I need to define a 'default' bucket? If so how?

Can I also setup additional buckets? I don't mean via templates... Can you point me in the right direction for this, and would the code need to also include the 'default' bucket?

Many thanks, would like to get this correct BEFORE we start adding content so the right assets end up in the right buckets.