error opening documents office web apps or creating new document

I have installed SharePoint 2013 with Office Web Apps 2013 using http.

Everything appears to be ok, but when I try to create a new document I get a an error: Microsoft ... Web App. Sorry, we ran into a problem. Please try again. However, the document is created.

When I try to open or preview an existing document I get an error: Microsoft ... Web App. Sorry, we couldn't open this ...

I only see one error on the WAC server. Error 8115