I'm facing an error while I select a new db in localhost. First an Internal Server Error Screen comes then when I reload the page,the page will come. But because of this error we can't view the code in Edit Form View and many other problems like we can't edit the reports. I think this is because of some missing packages.If anyone has a list of what all packages to be installed for the correct working or any other methods to resolve this issue, Please help..

Error Log

ERROR ? werkzeug: Error on request: Traceback (most recent call last): File "/usr/local/lib/python2.7/dist-packages/werkzeug/serving.py", line 270, in run_wsgi execute(self.server.app) File "/usr/local/lib/python2.7/dist-packages/werkzeug/serving.py", line 258, in execute application_iter = app(environ, start_response) File "/home/orchid/Documents/client_projects/Aasons/live/live/odoo/odoo/service/server.py", line 250, in app return self.app(e, s) File "/home/orchid/Documents/client_projects/Aasons/live/live/odoo/odoo/service/wsgi_server.py", line 184, in application return application_unproxied(environ, start_response) File "/home/orchid/Documents/client_projects/Aasons/live/live/odoo/odoo/service/wsgi_server.py", line 170, in application_unproxied result = handler(environ, start_response) File "/home/orchid/Documents/client_projects/Aasons/live/live/odoo/odoo/http.py", line 1307, in callself.load_addons() File "/home/orchid/Documents/client_projects/Aasons/live/live/odoo/odoo/http.py", line 1328, in load_addons m = import('odoo.addons.' + module) File "/home/orchid/Documents/client_projects/Aasons/live/live/odoo/odoo/modules/module.py", line 81, in load_module execfile(modfile, new_mod.dict) File "/usr/lib/python2.7/dist-packages/odoo/addons/l10n_fr_pos_cert/init.py", line 6, in from ..l10n_fr_certification.models.res_company import UNALTERABLE_COUNTRIES ImportError: cannot import name UNALTERABLE_COUNTRIES