As requested:

File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/http.py", line 654, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/http.py", line 312, in _handle_exception
    raise pycompat.reraise(type(exception), exception, sys.exc_info()[2])
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/tools/pycompat.py", line 87, in reraise
    raise value
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/http.py", line 696, in dispatch
    result = self._call_function(**self.params)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/http.py", line 344, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/service/model.py", line 97, in wrapper
    return f(dbname, *args, **kwargs)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/http.py", line 337, in checked_call
    result = self.endpoint(*a, **kw)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/http.py", line 939, in __call__
    return self.method(*args, **kw)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/http.py", line 517, in response_wrap
    response = f(*args, **kw)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/addons/web/controllers/main.py", line 962, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/addons/web/controllers/main.py", line 954, in _call_kw
    return call_kw(request.env[model], method, args, kwargs)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/api.py", line 749, in call_kw
    return _call_kw_multi(method, model, args, kwargs)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/api.py", line 736, in _call_kw_multi
    result = method(recs, *args, **kwargs)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/models.py", line 5394, in onchange
    record = self.new(values)
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/models.py", line 4869, in new
    record._cache.update(record._convert_to_cache(values, update=True))
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/models.py", line 4742, in _convert_to_cache
    for name, value in values.items()
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/models.py", line 4743, in <dictcomp>
    if name in fields
  File "/opt/bitnami/apps/odoo/lib/odoo-12.0.post20181218-py3.7.egg/odoo/fields.py", line 1952, in convert_to_cache
    raise ValueError("Wrong value for %s: %r" % (self, value))
ValueError: Wrong value for res.partner.lang: 'en_US'

------end traceback----