i finally finished "infected" (ground and space) but i can't hail starfleet.
in the to-do-list the next step is "hail starflleet", but the button is grey an unclickable.

i had the problem often with other mission, which i had to restart, but i really don't want to start "infected" one more time.
Comments
The mission you now have in your inventory is legacy and uncompleteable... Quite simply it is a lefover from before Season 4... A mission you never turned in.
To play Infected, Cure or Khitomer now, you have to open the PvE queue and sign up for one of the missions.
To play any of the Borg STF's: Find your minimap, click the down arrow, select "PvE Queues".
There they are.
There is no "mission" for them now, and only 60 mins cooldown.
Oh... and you can drop the mission in your journal.
that's good to know!
thank you!
Yup... Sadly you wont det the Borg engine you've earned when you got the mission, but you can get another one now for 5 ECD's