We can associate activities with entity records even though they are closed (in inactive state) because CRM setup 1:N relationship with activity and other activities related entities if Activities checkbox is selected under entity definition. But let’s say we have business requirement to stop this behavior. There is no out of the box setting to disable it, but we can implement this requirement by simply creating a quick real time workflow.

Let’s see how we can implement this. Suppose we want to stop user from creating appointment for closed lead. We can follow below steps:

1. Navigate to Settings-> Processes and select New.
2. Enter details like below and click on Ok :

3. Change workflow Scope to organization.
4. Click on Add Step dropdown and add Check Condition step

5. Click on Condition hyper link and configure it like below screen:

6. Finally click on the immediate line under if and add Stop Workflow step under Add Step dropdown.
7. Select workflow status as Canceled and click on Set Properties button and write “You can’t create Appointment for Closed Leads” under value text box.

8. Activate workflow and we are done!!
Now if user will try to set appointment for closed lead he will get error like below

Similarly we can create more workflow for other activity types if required.