Hi, we are using Odoo v19 Online, and we´re getting a "" error when doing the following: On a MO, manually inputting the quantity to produce, for example "650 / 650 units". Then clicling on "Details" of any component to modify lot number etc. We´ve found a work around which is: not inputing manually the quantity to produce (for example, leave it as 0 / 650 units" editing the lot numbers (the error doesnt pop up this way) clicking on "Produce all" at the end However this will not be of use i

This error is not just a generic singleton issue — in MOs it is usually triggered by inconsistent or missing UoM data during quantity recomputation. In our case (Odoo 19 Online), we can consistently reproduce it with this flow: Set “Quantity to Produce” manually (e.g. 650 / 650) Open component “Details” Modify lot/serial → error is raised The traceback shows it crashes during _set_quantity_done, specifically when Odoo tries to compare quantities using: ml.product_id.uom_id.compare(...) So the re

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ValueError: Expected singleton: uom.uom() in MOs

uom singletonissue

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Nutrición y Suplementos del Bajío, msarachaga@nsb.com.mx

Hi, we are using Odoo v19 Online, and we´re getting a "" error when doing the following:

On a MO, manually inputting the quantity to produce, for example "650 / 650 units".
Then clicling on "Details" of any component to modify lot number etc.

We´ve found a work around which is:

not inputing manually the quantity to produce (for example, leave it as 0 / 650 units"
editing the lot numbers (the error doesnt pop up this way)
clicking on "Produce all" at the end

However this will not be of use if the produced quantity is different from the planned quantity of the MO.

Full error below:

RPC_ERROR

Odoo Server Error

Occured on nsbmx.odoo.com on model mrp.production on 2026-04-02 14:25:19 GMT

Traceback (most recent call last):
  File "/home/odoo/src/odoo/19.0/odoo/orm/models.py", line 5937, in ensure_one
    _id, = self._ids
    ^^^^
ValueError: not enough values to unpack (expected 1, got 0)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/odoo/src/odoo/19.0/odoo/http.py", line 2298, in _serve_db
    return service_model.retrying(serve_func, env=self.env)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/odoo/service/model.py", line 188, in retrying
    result = func()
             ^^^^^^
  File "/home/odoo/src/odoo/19.0/odoo/http.py", line 2353, in _serve_ir_http
    response = self.dispatcher.dispatch(rule.endpoint, args)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/odoo/http.py", line 2568, in dispatch
    result = self.request.registry['ir.http']._dispatch(endpoint)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/odoo/addons/base/models/ir_http.py", line 355, in _dispatch
    result = endpoint(**request.params)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/odoo/http.py", line 808, in route_wrapper
    result = endpoint(self, *args, **params_ok)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/web/controllers/dataset.py", line 32, in call_kw
    return call_kw(request.env[model], method, args, kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/odoo/service/model.py", line 97, in call_kw
    result = method(recs, *args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/web/models/models.py", line 88, in web_save
    self.write(vals)
  File "/home/odoo/src/odoo/19.0/addons/base_automation/models/base_automation.py", line 896, in write
    write.origin(self.with_env(automations.env), vals, **kw)
  File "/home/odoo/src/enterprise/19.0/project_mrp_workorder_account/models/mrp_production.py", line 11, in write
    res = super().write(vals)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/project_mrp_account/models/mrp_production.py", line 28, in write
    res = super().write(vals)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/enterprise/19.0/mrp_workorder/models/mrp_production.py", line 37, in write
    res = super().write(vals)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/mrp_account/models/mrp_production.py", line 28, in write
    res = super().write(vals)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/mrp/models/mrp_production.py", line 1038, in write
    res = super(MrpProduction, self).write(vals)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/mail/models/mail_thread.py", line 391, in write
    result = super().write(vals)
             ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/enterprise/19.0/ai_fields/models/models.py", line 57, in write
    res = super().write(vals)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/odoo/orm/models.py", line 4469, in write
    field.write(self, value)
  File "/home/odoo/src/odoo/19.0/odoo/orm/fields_relational.py", line 733, in write
    self.write_batch([(records, value)])
  File "/home/odoo/src/odoo/19.0/odoo/orm/fields_relational.py", line 754, in write_batch
    self.write_real(records_commands_list, create)
  File "/home/odoo/src/odoo/19.0/odoo/orm/fields_relational.py", line 1012, in write_real
    comodel.browse(command[1]).with_prefetch(prefetch_ids).write(command[2])
  File "/home/odoo/src/odoo/19.0/addons/repair/models/stock_move.py", line 117, in write
    res = super().write(vals)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/sale_stock/models/stock.py", line 129, in write
    res = super().write(vals)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/stock_picking_batch/models/stock_move.py", line 30, in write
    res = super().write(vals)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/mrp/models/stock_move.py", line 303, in write
    res = super().write(vals)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/stock/models/stock_move.py", line 789, in write
    res = super().write(vals)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/enterprise/19.0/ai_fields/models/models.py", line 57, in write
    res = super().write(vals)
          ^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/odoo/orm/models.py", line 4501, in write
    fields[0].determine_inverse(real_recs)
  File "/home/odoo/src/odoo/19.0/odoo/orm/fields.py", line 1926, in determine_inverse
    determine(self.inverse, records)
  File "/home/odoo/src/odoo/19.0/odoo/orm/fields.py", line 81, in determine
    return needle(*args)
           ^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/stock/models/stock_move.py", line 475, in _set_quantity
    _process_increase(move, delta_qty)
  File "/home/odoo/src/odoo/19.0/addons/stock/models/stock_move.py", line 461, in _process_increase
    move._set_quantity_done(move.quantity)
  File "/home/odoo/src/odoo/19.0/addons/stock/models/stock_move.py", line 2409, in _set_quantity_done
    self.move_line_ids = self._set_quantity_done_prepare_vals(qty)
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/stock/models/stock_move.py", line 2339, in _set_quantity_done_prepare_vals
    if ml.product_id.uom_id.compare(ml_qty, qty) > 0:
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/odoo/src/odoo/19.0/addons/uom/models/uom_uom.py", line 129, in compare
    self.ensure_one()
  File "/home/odoo/src/odoo/19.0/odoo/orm/models.py", line 5940, in ensure_one
    raise ValueError("Expected singleton: %s" % self)
ValueError: Expected singleton: uom.uom()

The above server error caused the following client error:
RPC_ERROR: Odoo Server Error
    RPC_ERROR
        at makeErrorFromResponse (https://nsbmx.odoo.com/web/assets/0b06ec6/web.assets_web.min.js:3198:165)
        at XMLHttpRequest.<anonymous> (https://nsbmx.odoo.com/web/assets/0b0

Codesphere Tech

Hello,
Please update Stock App.
let me know it is not resolved
Thanks

Ravi Durga Prasad

This error is not just a generic singleton issue — in MOs it is usually triggered by inconsistent or missing UoM data during quantity recomputation.

In our case (Odoo 19 Online), we can consistently reproduce it with this flow:

Set “Quantity to Produce” manually (e.g. 650 / 650)
Open component “Details”
Modify lot/serial → error is raised

The traceback shows it crashes during _set_quantity_done, specifically when Odoo tries to compare quantities using:

ml.product_id.uom_id.compare(...)

So the real problem is that at least one move line ends up with:

missing product_uom_id, or
inconsistent UoM vs product UoM

This aligns with how singleton errors occur in Odoo — the ORM expects a single valid record but receives an empty or invalid recordset instead (Odoo).

Temporary workaround:

Do NOT manually set the quantity first
Edit lot numbers while quantity is still 0
Then click “Produce All”

This avoids triggering _set_quantity_done too early.

However, the proper fix is to check:

All component products have a valid UoM
BOM lines use consistent UoM categories
No automation/custom module is altering move lines during write()

In our case, the issue seems tied to recomputation timing rather than user input alone, so it may also be a regression in v19.

Would be useful to confirm if others are seeing this specifically when editing lot numbers after manually setting the production quantity.

Zehntech Technologies Inc.

Hello,

This issue is typically related to a mismatch or inconsistency in the Unit of Measure (UoM) or stock move lines when the quantity to produce is manually updated before editing component details.

In Odoo Online (v19), this behavior is not expected and may indicate a bug or an edge-case scenario in the manufacturing flow—especially when modifying quantities prior to lot/serial assignment.

As a workaround, your current approach is correct. However, to properly handle cases where produced quantity differs from planned quantity, you may consider:

Adjusting quantities after assigning lot/serial numbers, or
Reviewing the UoM configuration for the product and its components to ensure consistency

If the issue persists, it would be advisable to report it to Odoo support, as it may require a fix on their side (especially in Online version where custom fixes are limited).

Hope this works for you! Feel free to reach out for further discussion.

Regards,

Zehntech Technologies Inc.

santosh.sekwadia@zehntech.com

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