Hey,

I've tried to delete some products but it won't let me, I get this error

Error:
Odoo Server Error

Traceback (most recent call last):
File "/home/odoo/src/odoo/odoo/addons/base/models/ir_http.py", line 237, in _dispatch
result = request.dispatch()
File "/home/odoo/src/odoo/odoo/http.py", line 684, in dispatch
result = self._call_function(**self.params)
File "/home/odoo/src/odoo/odoo/http.py", line 360, in _call_function
return checked_call(self.db, *args, **kwargs)
File "/home/odoo/src/odoo/odoo/service/model.py", line 94, in wrapper
return f(dbname, *args, **kwargs)
File "/home/odoo/src/odoo/odoo/http.py", line 348, in checked_call
result = self.endpoint(*a, **kw)
File "/home/odoo/src/odoo/odoo/http.py", line 913, in __call__
return self.method(*args, **kw)
File "/home/odoo/src/odoo/odoo/http.py", line 532, in response_wrap
response = f(*args, **kw)
File "/home/odoo/src/odoo/addons/web/controllers/main.py", line 1389, in call_kw
return self._call_kw(model, method, args, kwargs)
File "/home/odoo/src/odoo/addons/web/controllers/main.py", line 1381, in _call_kw
return call_kw(request.env[model], method, args, kwargs)
File "/home/odoo/src/odoo/odoo/api.py", line 399, in call_kw
result = _call_kw_multi(method, model, args, kwargs)
File "/home/odoo/src/odoo/odoo/api.py", line 386, in _call_kw_multi
result = method(recs, *args, **kwargs)
File "/home/odoo/src/odoo/addons/sale_timesheet/models/product.py", line 91, in unlink
time_product = self.env.ref('sale_timesheet.time_product')
File "/home/odoo/src/odoo/odoo/api.py", line 514, in ref
return self['ir.model.data'].xmlid_to_object(xml_id, raise_if_not_found=raise_if_not_found)
File "/home/odoo/src/odoo/odoo/addons/base/models/ir_model.py", line 1944, in xmlid_to_object
t = self.xmlid_to_res_model_res_id(xmlid, raise_if_not_found)
File "/home/odoo/src/odoo/odoo/addons/base/models/ir_model.py", line 1928, in xmlid_to_res_model_res_id
return self.xmlid_lookup(xmlid)[1:3]
File "", line 2, in xmlid_lookup
File "/home/odoo/src/odoo/odoo/tools/cache.py", line 90, in lookup
value = d[key] = self.method(*args, **kwargs)
File "/home/odoo/src/odoo/odoo/addons/base/models/ir_model.py", line 1921, in xmlid_lookup
raise ValueError('External ID not found in the system: %s' % xmlid)
Exception

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/home/odoo/src/odoo/odoo/http.py", line 640, in _handle_exception
return super(JsonRequest, self)._handle_exception(exception)
File "/home/odoo/src/odoo/odoo/http.py", line 316, in _handle_exception
raise exception.with_traceback(None) from new_cause
ValueError: External ID not found in the system: sale_timesheet.time_product