I'm not sure what happened, but today I realized today that I am unable to add any items to an invoice. I get this error:

Error: KeyError: 'shop_id'

Any idea how to fix it? I am assuming I did something I shouldn't have, but I have no idea what that might have been, as I haven't touched it in awhile. I'm on OpenERP 7. Thank you!

Edit: There is no error displayed in the log, but here is the output when I click to add an item to the Sales Order:

2015-01-21 21:08:09,929 21943 INFO WIS werkzeug: 127.0.0.1 - - [21/Jan/2015 21:08:09] "POST /web/dataset/call_kw/sale.order.line:default_get HTTP/1.0" 200 -

2015-01-21 21:08:10,001 21943 INFO WIS werkzeug: 127.0.0.1 - - [21/Jan/2015 21:08:10] "POST /web/dataset/call_kw/sale.order.line:product_uom_change HTTP/1.0" 200 -

2015-01-21 21:08:10,032 21943 INFO WIS werkzeug: 127.0.0.1 - - [21/Jan/2015 21:08:10] "POST /web/dataset/call_kw/product.uom:name_get HTTP/1.0" 200 - 

I would be happy to provide more info if there is a way to get more detailed output

Also, I have found a clue that might be related to this - multi_company and sale_stock are listed under modules to update, although when I click Update, I get an XML architecture view error..which seems odd here, and then it doesn't upgrade

The parse error is on /usr/lib/pymodules/python2.7/openerp/addons/sale_stock/sale_stock_view.xml, which is 

        <record id="view_order_form_inherit" model="ir.ui.view"