Odoo 12 - Model not found even though it exists - python-3.x

Question

I am porting a localization accountability model from Odoo 8 to Odoo 12, I ported a function that worked flawlessly but then right after that I tried porting some other code that does not interfere with the first on, even though, whenever it is initialized by the init.py Odoo brings up an error telling me that the model cannot be found, even though it is correctly set up.
All I've tried is to ignore the new modules I added right after setting up the one that should be perfectly working right now. Without them (or without any new module at all, because I've tried porting different ones) it works, but this shouldn't be the case at all.
wizard_nro_ctrl.py
class WizNroctrl(models.TransientModel):
_name = 'nroctrl'
_description = "Wizard that changes the invoice control number"
new_nroctrl = fields.Char('Control Number', required=True)
sure = fields.Boolean('Are you sure?')
# Change control number of the invoice
def set_noctrl(self):
if not self.sure:
raise except_orm('Error!', 'Please confirm that you want to do this by checking the option')
current_id = self._context['current_id']
inv_object = self.env['account.invoice'].browse(current_id)
inv_object.nro_ctrl = self.new_nroctrl
return True
wizard_nro_ctrl_view.xml
<?xml version='1.0' encoding='UTF-8'?>
<odoo>
<data>
<record model="ir.ui.view" id="wizard_nro_ctrl_form">
<field name="name">wizard.nro.ctrl.form</field>
<field name="model">nroctrl</field>
<field name="arch" type="xml">
<form string="Changing the Control Number">
<field name="new_nroctrl" placeholder="New control number"/>
<separator string="Are you sure you want to do this?" colspan="4"/>
<field name="sure"/>
<footer>
<button name="set_noctrl" string="Confirm" type="object"/>
<button special="cancel" string="Cancel"/>
</footer>
</form>
</field>
</record>
<record id="action_wiz_nroctrl" model="ir.actions.act_window">
<field name="name">Change control number</field>
<field name="type">ir.actions.act_window</field>
<field name="model">wiz.nroctrl</field>
<field name="view_type">form</field>
<field name="view_mode">form</field>
<field name="target">new</field>
</record>
</data>
</odoo>
The init.py has the model initialized and the folder as well.
The model should work just fine, without this error. There's no reason to my knowledge for this issue.
odoo.tools.convert.ParseError: "Error while validating constraint
Model not found: nroctrl

Answer 1

Please make sure that in the model action you have wrote include model name 'nroctrl'. give the below xml code (nroctrl):
<record id="action_wiz_nroctrl" model="ir.actions.act_window">
<field name="name">Change control number</field>
<field name="type">ir.actions.act_window</field>
<field name="model">nroctrl</field>
<field name="view_type">form</field>
<field name="view_mode">form</field>
<field name="target">new</field>
</record>
Also please ensure that you have given file name in init.py of wizard folder. also the folder name in ini.py of module.