Unable to add DL to sharepoint permissions

Issue
 whenever you try to add a DL to sharepoint permissions, it doesn't resolve and gives an error

Resolution
 If you want to add any DL to the sharepoint permissions, it should be converted to Security Groups. As soon as that is converted to Security Group it will be resolved in the permissions section and users will be able to access the site.

Note: If those DL's are having SUB DL's inside it , then they should also be converted to Security Groups.