On macos:

GOG Galaxy shows "5.034 Extensions" "1 DLC"

Upon opening, it shows "OS 5.060"

My labyrinths save game won't start.

"Save is configured for Labyrinths DLC, but it is not installed on this computer."

I've tried uninstall/reinstall, and uninstall DLC, reinstall DLC, to no effect.

OS 5.060 is the same as what I can see but the game does continue my finished save (I just checked it for you).
Weird. :/

I'm actually right in the middle of Labyrinths, even though I finished the main storyline.

Still fails on 5.068.

Still fails on 5.069.

I recently purchased both Hacknet and its DLC Versions 5.069 and propably got the same problem.

I've installed both on MacOS 10.12.6.

The starting screen after launch shows me "Hacknet OS v5.069", no mention of Labyrinths to be seen (see attached screenshot).

I completed the main campaign yesterday and did not receive any of the DLC missions neither via Entropy nor CSEC.

So Labyrinths doesn't seem to be installed correctly. Did anybody find any solutions for this, yet?

I would suggest contacting GOG support. They'll to be able to reproduce this problem so they can find out what the cause is.