please help for this situation facing. the Next Activity (x_activity_type_id) is my custom field which set NOT Save means Next Activity (x_activity_type_id) is a Transient field.

i have created an Action, 

Model = Activity (mail.activity), 

Action To Do = Create Next Activity,

Trigger = On Update, 

Trigger Fields = Next Activity (my custom field which will not Save)

Before Update Domain = Next Activity = is not set

Apply On = Next Activity = is set

Activity = Meeting

Due Date in = 1 Days

Activity User Type = Generic User From Record

User Field Name = user_id 

Summary = abcd

in CRM Pipeline i am going to Edit an Activity, set Next Activity = Meeting when Save it throws Error

RPC Error

Odoo Server Error

Traceback (most recent call last):

--- lines here deleted due to format problem... ---

File "D:\Program Files\Odoo 16.0e.20230607\server\odoo\addons\mail\models\ir_actions_server.py", line 248, in _run_action_next_activity

record.activity_schedule(**vals)

AttributeError: 'mail.activity' object has no attribute 'activity_schedule'

The above server error caused the following client error:

null

failed to understand what is the problem here and how to resolve it, please help.

regards