I can't complete the task "attack on the lab"

Halo.I can’t complete the task “attack on the lab”.already five matches in a row 8 out of 10,though the check boxes on the ruined fortresses of mine.Need help

Hey Urman,

Thanks for the report! Are you playing with a hero that can destroy Structures at a long distance? There is currently an issue where the quest can fail to grant credit if you are not within a certain range of the structure.

Thanks,
~ Fizivix