Here is a methode to patch your system if any field is missing. I used this offen before :-)

1. create new folder in your addons. Nem like repair_temp

2. create a 3 new file.

- __init.__.py

 import sale

- openerp.py

{
    "name" : "Missing field",
    "version" : "0.1",
    "author" : "You name",
    "website" : "",
    "category" : "Generic Modules/Others",
    "depends" : ["base",'sale'],
    "description" : """repair missing field""",
    "init_xml" : [],
    "demo_xml" : [],
    'update_xml': [],
    "images" : [],   
    "installable": True
}

- sale.py

class sale_order(osv.osv):

    _name = 'sale_order'
    _inherit = 'sale_order'
    _columns = {

                'is_template':fields.boolean('Template?'), 
               
            }    
   

sale_order()    

3. Install your patch module

>refresh the modules list in technical section, or Settings

Install your new module, which name must be the folder name.

Please note I didn't test it, just wrote down, please note that I use 6.1 so may it not works as well in 7.0 or 8.0.  if you have any problem, please comment the trouble. U can get more info about the system if you start the Erp with --debug key.