Error:
Odoo Server Error

Traceback (most recent call last):
  File "/data/build/odoo/odoo/http.py", line 624, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/data/build/odoo/odoo/http.py", line 310, in _handle_exception
    raise pycompat.reraise(type(exception), exception, sys.exc_info()[2])
  File "/data/build/odoo/odoo/tools/pycompat.py", line 14, in reraise
    raise value
  File "/data/build/odoo/odoo/http.py", line 669, in dispatch
    result = self._call_function(**self.params)
  File "/data/build/odoo/odoo/http.py", line 350, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/data/build/odoo/odoo/service/model.py", line 94, in wrapper
    return f(dbname, *args, **kwargs)
  File "/data/build/odoo/odoo/http.py", line 339, in checked_call
    result = self.endpoint(*a, **kw)
  File "/data/build/odoo/odoo/http.py", line 915, in __call__
    return self.method(*args, **kw)
  File "/data/build/odoo/odoo/http.py", line 515, in response_wrap
    response = f(*args, **kw)
  File "/data/build/odoo/addons/web/controllers/main.py", line 1339, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/data/build/odoo/addons/web/controllers/main.py", line 1331, in _call_kw
    return call_kw(request.env[model], method, args, kwargs)
  File "/data/build/odoo/odoo/api.py", line 388, in call_kw
    model.flush()
  File "/data/build/odoo/odoo/models.py", line 5499, in flush
    self.recompute()
  File "/data/build/odoo/odoo/models.py", line 5941, in recompute
    process(field)
  File "/data/build/odoo/odoo/models.py", line 5925, in process
    recs.mapped(field.name)
  File "/data/build/odoo/odoo/models.py", line 5307, in mapped
    recs = recs._mapped_func(operator.itemgetter(name))
  File "/data/build/odoo/odoo/models.py", line 5266, in _mapped_func
    vals = [func(rec) for rec in self]
  File "/data/build/odoo/odoo/models.py", line 5266, in <listcomp>
    vals = [func(rec) for rec in self]
  File "/data/build/odoo/odoo/models.py", line 5731, in __getitem__
    return self._fields[key].__get__(self, type(self))
  File "/data/build/odoo/odoo/fields.py", line 1032, in __get__
    self.compute_value(recs)
  File "/data/build/odoo/odoo/fields.py", line 1146, in compute_value
    records._compute_field_value(self)
  File "/data/build/odoo/odoo/models.py", line 4003, in _compute_field_value
    getattr(self, field.compute)()
  File "/data/build/odoo/addons/account/models/account_move.py", line 3345, in _compute_tax_audit
    audit_str += report_line.tag_name + ': ' + formatLang(self.env, tag_amount, currency_obj=currency)
TypeError: unsupported operand type(s) for +: 'bool' and 'str'