Odoo Server Error

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/odoo/api.py", line 745, in get
    value = self._data[field][record._ids[0]]
KeyError: 27

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/odoo/fields.py", line 1002, in __get__
    value = env.cache.get(record, self)
  File "/usr/lib/python3/dist-packages/odoo/api.py", line 751, in get
    raise CacheMiss(record, field)
odoo.exceptions.CacheMiss: ('purchase.order(27,).text_message', None)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/odoo/http.py", line 624, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/usr/lib/python3/dist-packages/odoo/http.py", line 310, in _handle_exception
    raise pycompat.reraise(type(exception), exception, sys.exc_info()[2])
  File "/usr/lib/python3/dist-packages/odoo/tools/pycompat.py", line 14, in reraise
    raise value
  File "/usr/lib/python3/dist-packages/odoo/http.py", line 669, in dispatch
    result = self._call_function(**self.params)
  File "/usr/lib/python3/dist-packages/odoo/http.py", line 350, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/usr/lib/python3/dist-packages/odoo/service/model.py", line 94, in wrapper
    return f(dbname, *args, **kwargs)
  File "/usr/lib/python3/dist-packages/odoo/http.py", line 339, in checked_call
    result = self.endpoint(*a, **kw)
  File "/usr/lib/python3/dist-packages/odoo/http.py", line 915, in __call__
    return self.method(*args, **kw)
  File "/usr/lib/python3/dist-packages/odoo/http.py", line 515, in response_wrap
    response = f(*args, **kw)
  File "/usr/lib/python3/dist-packages/odoo/addons/web/controllers/main.py", line 1322, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/usr/lib/python3/dist-packages/odoo/addons/web/controllers/main.py", line 1314, in _call_kw
    return call_kw(request.env[model], method, args, kwargs)
  File "/usr/lib/python3/dist-packages/odoo/api.py", line 387, in call_kw
    result = _call_kw_multi(method, model, args, kwargs)
  File "/usr/lib/python3/dist-packages/odoo/api.py", line 374, in _call_kw_multi
    result = method(recs, *args, **kwargs)
  File "/usr/lib/python3/dist-packages/odoo/models.py", line 2918, in read
    vals[name] = convert(record[name], record, use_name_get)
  File "/usr/lib/python3/dist-packages/odoo/models.py", line 5644, in __getitem__
    return self._fields[key].__get__(self, type(self))
  File "/usr/lib/python3/dist-packages/odoo/fields.py", line 1026, in __get__
    self.compute_value(recs)
  File "/usr/lib/python3/dist-packages/odoo/fields.py", line 1111, in compute_value
    records._compute_field_value(self)
  File "/usr/lib/python3/dist-packages/odoo/models.py", line 3939, in _compute_field_value
    getattr(self, field.compute)()
  File "/usr/lib/python3/dist-packages/odoo/addons/sh_whatsapp_integration/models/purchase_order_inherit.py", line 49, in get_message_detail_po
    txt_message +=  "%0A"+"*"+purchase_line.product_id.name+"*"+"%0A"+"*Qty:* "+str(purchase_line.product_qty)+"%0A"+"*Price:* "+str(purchase_line.price_unit)+""+str(purchase_line.order_id.currency_id.symbol)+"%0A"+"________________________"+"%0A"
TypeError: can only concatenate str (not "bool") to str

When ever I tried to make RFQ this happen and it dont let me save the RFQ Help work be Highly appricate
I am using Whatsapp Module sh_whatsapp_intergation 
and base_accounting
and statement report