I am playing Deus Ex: Revision and I have found the aug canister in the MJ12 facility.
When I install and then activate the spy drone I receive the following message:
'Spy Drone activated'
'Reconstruction will be completed in 75289 seconds' (these seconds do count down)
'Spy Drone deactivated'

75000 seconds is just over 20 hours.

What on earth is going on here and how do I fix it?

Thank you for any help.

So I believe I have figured out what happened.
I noticed that everything with a recharge, such as medbots, also had this massive count down timer.

I was able to fix the error by loading a previous save where it was not present.

I later recreated the error as follows:
I pressed the snooze button on my laptop, then woke up the laptop, then went immediately into the game and quick saved. Then I exited the game and reloaded that save and the error had returned. It was now at just over 50000 seconds (I believe there is some sort of global countdown in the game).

So that is what causes the error: saving and loading after snoozing the laptop.