I have been following the module creation tutorial (https://www.odoo.com/documentation/9.0/howtos/backend.html) and it simply doesn't work. 

I think it is something to do with the files that the tutorial mentions are inconsistent with the files created by the scaffold command, but I can't work out how to resolve the issues.

I followed the steps, but got an error saying: 

ParseError: "Invalid model name in the action definition.

None" while parsing /etc/odoo/addons/asn_upload/views/asn_upload.xml:42, near

<record model="ir.actions.act_window" id="action_asn_upload">

<field name="name">AsnFile</field>

<field name="res_model">asn_upload.asn_file</field>

<field name="view_type">form</field>

<field name="view_mode">tree,form</field>

<field name="help" type="html">

<p class="oe_view_nocontent_create">Add a ASN file</p>

</field>

</record>