Hi Solanki,

I have also faced same situation, inspite of closing the project we can create tasks and issues, etc for that project. So, what I did is 

1) hided the buttons(Task, Issues, etc) on project form, once it reaches to the dead state by applying attrs on buttons div.

2) at task, issue, milestone, etc masters on project_id field applied the domain ('state', '!=', 'closed').

3) Rest wherever u get the project_id field(related to project master) apply ('state', '!=', 'closed') domain .

Now i cant create the tasks or issues or anything from any scenario.

thanks