# Error when cancelling customer shipment
**URL:** https://discuss.tryton.org/t/error-when-cancelling-customer-shipment/8255
**Category:** Developer
**Tags:** sales
**Created:** [January 28, 2025, 12:33pm UTC](https://discuss.tryton.org/t/error-when-cancelling-customer-shipment/8255 "2025-01-28T12:33:44Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@jt93](https://discuss.tryton.org/u/jt93)
#### Post date: [January 28, 2025, 12:33pm UTC](https://discuss.tryton.org/t/error-when-cancelling-customer-shipment/8255/1 "2025-01-28T12:33:44Z")
Hi,
when I try to cancel a customer shipment I get the following error with tryton 7.4:
```auto
trytond/modules/stock_shipment_measurements/stock.py", line 182, in cancel
if issubclass(move.shipment, MeasurementsMixin):
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: issubclass() arg 1 must be a class
```
At first I thought its a small bug, but when I use `type(move.shipment)` instead to get the class, I get another error:
```auto
trytond/modules/stock_shipment_measurements/stock.py", line 185, in cancel
Shipment.set_measurements(shipments)
File "trytond/trytond/modules/stock_shipment_measurements/stock.py", line 318, in set_measurements
cls.write(shipments, {})
File "trytond/trytond/modules/stock/shipment.py", line 1779, in write
super(ShipmentOut, cls).write(*args)
File "trytond/trytond/model/modelsql.py", line 275, in wrapper
return func(cls, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "trytond/trytond/model/modelsql.py", line 1380, in write
sum(((records, values) + args)[0:None:2], [])))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: can only concatenate list (not "set") to list
```
Am I missing something here? Any help is appreciated.
Thanks
---
### Author:  [@pokoli](https://discuss.tryton.org/u/pokoli)
#### Post date: [January 28, 2025, 1:30pm UTC](https://discuss.tryton.org/t/error-when-cancelling-customer-shipment/8255/2 "2025-01-28T13:30:22Z")
> [@jt93](#):
>
> ```auto
> trytond/modules/stock_shipment_measurements/stock.py", line 182, in cancel
> if issubclass(move.shipment, MeasurementsMixin):
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> TypeError: issubclass() arg 1 must be a class
>
> ```
I guess you should use `isinstance` instead of `isssubclass` to fix it.
Could you please fill an issue in the [bug tracker](https://bugs.tryton.org/)?
If you want to contribute the fix back to the project, make sure to read our h[ow to develop](https://www.tryton.org/develop) page.
Thanks for your effort on this!
---
### Author:  [@jt93](https://discuss.tryton.org/u/jt93)
#### Post date: [January 28, 2025, 4:24pm UTC](https://discuss.tryton.org/t/error-when-cancelling-customer-shipment/8255/3 "2025-01-28T16:24:52Z")
Thanks for your reply. Using `isinstance()` solves the first problem and I created an [issue](https://foss.heptapod.net/tryton/tryton/-/issues/13842). However, the second problem appearing afterwards seems to be a bigger one. Could it be another Bug, or some wrong configuration on my side?
Thanks
---
### Author:  [@dotbit](https://discuss.tryton.org/u/dotbit)
#### Post date: [January 29, 2025, 5:37am UTC](https://discuss.tryton.org/t/error-when-cancelling-customer-shipment/8255/4 "2025-01-29T05:37:40Z")
In fully updated 7.4 I get the following while trying to delete a shipment that was created from sale:
```auto
Traceback (most recent call last):
File "/trytond/wsgi.py", line 96, in dispatch_request
return endpoint(request, **request.view_args)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/protocols/dispatcher.py", line 44, in rpc
return methods.get(request.rpc_method, _dispatch)(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/wsgi.py", line 76, in wrapper
return func(request, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/protocols/wrappers.py", line 206, in wrapper
result = func(request, pool, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/protocols/dispatcher.py", line 216, in _dispatch
result = rpc.result(meth(*c_args, **c_kwargs))
^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/modules/stock/shipment.py", line 1798, in delete
cls.cancel(shipments)
File "/trytond/model/modelview.py", line 764, in wrapper
return func(cls, records, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/modules/stock_shipment_measurements/stock.py", line 461, in wrapper
result = func(cls, shipments, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/model/workflow.py", line 37, in wrapper
result = func(cls, filtered, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/modules/stock_shipment_measurements/stock.py", line 563, in cancel
super().cancel(shipments)
File "/trytond/model/modelview.py", line 764, in wrapper
return func(cls, records, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/model/workflow.py", line 37, in wrapper
result = func(cls, filtered, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/modules/sale_shipment_cost/stock.py", line 242, in cancel
super().cancel(shipments)
File "/trytond/model/modelview.py", line 764, in wrapper
return func(cls, records, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/model/workflow.py", line 37, in wrapper
result = func(cls, filtered, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/modules/sale/stock.py", line 25, in wrapper
func(cls, shipments)
File "/trytond/modules/sale/stock.py", line 71, in cancel
super(ShipmentOut, cls).cancel(shipments)
File "/trytond/model/modelview.py", line 764, in wrapper
return func(cls, records, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/model/workflow.py", line 37, in wrapper
result = func(cls, filtered, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/modules/stock/shipment.py", line 1734, in cancel
Move.cancel([m for s in shipments
File "/trytond/model/modelview.py", line 764, in wrapper
return func(cls, records, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/model/workflow.py", line 37, in wrapper
result = func(cls, filtered, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/trytond/modules/stock_shipment_measurements/stock.py", line 182, in cancel
if issubclass(move.shipment, MeasurementsMixin):
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: issubclass() arg 1 must be a class
Fault: issubclass() arg 1 must be a class
```
PS: My temporary fix is to first delete the outgoing moves, then I successfully delete the shipment without a crash.
Tested on [demo.tryton.org](http://demo.tryton.org) and I get the same crash after activating shipment measurements module.
> **[Error when cancelling customer shipment (#13842) · Issues · Tryton / Tryton ·...](https://foss.heptapod.net/tryton/tryton/-/issues/13843)**
>
> Cancelling a customer shipment does not work with the stock\_shipment\_measurements module activated. Reference: https://discuss.tryton.org/t/error-when-cancelling-customer-shipment/8255
---
### Author:  [@dotbit](https://discuss.tryton.org/u/dotbit)
#### Post date: [January 29, 2025, 6:49am UTC](https://discuss.tryton.org/t/error-when-cancelling-customer-shipment/8255/5 "2025-01-29T06:49:34Z")
@jt93 Do feel free to assign yourself to the issue I created.
---
### Author:  [@system](https://discuss.tryton.org/u/system)
#### Post date: [January 30, 2025, 6:50am UTC](https://discuss.tryton.org/t/error-when-cancelling-customer-shipment/8255/6 "2025-01-30T06:50:15Z")
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