After archiving a project in Jira I was still able to edit the issue in that project.

[tushargohel_crest]

I have Archived a project in Jira and I have a direct link to a issue in that particular project.

I access issue using direc link and tried to edit the issue and was able to edit it.

That should not be editable after archiving.

[Alex Christensen]

Yeah, you shouldn't be able to edit issues in archived projects. Did this issue happen to get moved into another project which is not archived, but the direct link to this issue still works since the old key is stored in the database? Do you see this message at the top of the issue?

[Joe Pitt]

What do you mean by Archive? The archive function is only available on the Data Center version. The standard workaround is to remove all permissions so it can't be seen or accessed by anyone except JIRA admins. 

[tushargohel_crest]

I am using Jira Data Center version 7.13.3 and there is a functionality to archive a project. 

[Joe Pitt]

You didn't have Data Center in the tags so I thought you just had server. I don't have experience with Data Center.