When i use the next commands to calculate my Total Volume an error come to my screen

below the lines and the error, this is made with Studio so it is not a very advanced lines but is just to calculate the volume of several products together

Dependencies:  move_ids_without_package

for record in self:
volume_m = 0
for line in record.move_ids_without_package :
volume_m += line.x_studio_volume_m3 * line.product_uom_qty
record['x_studio_volume_m'] = volume_m

and this is the error:

UncaughtClientError > TypeError

Uncaught Javascript Error > Cannot read properties of null (reading 'focusableElement')

TypeError: Cannot read properties of null (reading 'focusableElement')
    at FieldWrapper.getFocusableElement (https://newchanges2.odoo.com/web/assets/1474-fdd13ff/web.assets_backend.min.js:4292:55)
    at https://newchanges2.odoo.com/web/assets/1474-fdd13ff/web.assets_backend.min.js:5371:184
    at Function._.each._.forEach (https://newchanges2.odoo.com/web/assets/1473-bab63d1/web.assets_common.min.js:151:558)
    at toggleWidgets (https://newchanges2.odoo.com/web/assets/1474-fdd13ff/web.assets_backend.min.js:5371:133)
    at Class.unselectRow (https://newchanges2.odoo.com/web/assets/1474-fdd13ff/web.assets_backend.min.js:5372:1)
    at Class._onWindowClicked (https://newchanges2.odoo.com/web/assets/1474-fdd13ff/web.assets_backend.min.js:5435:6)
    at Class.trigger (https://newchanges2.odoo.com/web/assets/1473-bab63d1/web.assets_common.min.js:4857:180)
    at Class.trigger (https://newchanges2.odoo.com/web/assets/1473-bab63d1/web.assets_common.min.js:4863:148)
    at HTMLHtmlElement. (https://newchanges2.odoo.com/web/assets/1473-bab63d1/web.assets_common.min.js:5074:385)
    at HTMLHtmlElement.dispatch (https://newchanges2.odoo.com/web/assets/1473-bab63d1/web.assets_common.min.js:1787:447)