I've had this strange bug: I deactived the Remote Door Control system in the Electrical Center and returned to SCP-079's containment chamber.

Yet when, upon physically confronting it, I expected SCP-079 to give me the "Human, listen carefully..." speech, the computer presented me with an "X" immediately.

So I returned to the Electrical Center and reactivated the RDC system, then the game successfully played the "The doors at Gate B are now open" sequence (and the doors at Gate A and B were effectively unlocked).

So it's really only the delivery of the "Human, listen carefully..." sequence that failed on this occasion. There were other times when it did work.

EDIT: Game configuration: 1600x900, fullscreen, use launcher, difficulty: safe, map seed: de28x.

Looking at the code, it seems that the X is set to display once the sound channel containing the speech is no longer well, playing sound. It's likely that the speech just failed to load so it detected that the channel wasn't playing anything.

If you can replicate it, then maybe look at the console to see if it brought up a "Failed to load sound SFX/SCP/079/Speech.ogg". Regardless though there isn't really a way to fix this bug as the game can fail to load sounds at any point.

speedrunning strat 1005%

Thanks for your answer, Commander! I'll start using the console to watch for error messages from now on.

“Okay, double post all you want, but let me out of here, damn it.”

Hurray! I just got to SCP-079 in another playthrough and the same thing happened.

The console indeed revealed that the file "Speech.ogg" failed to play, and there was also a cascade of error messages for SCP-079's theme apparently, even though the theme was playing.

However it just so happened that the game had come to the point of overloading, as the textures had started to flicker.

After turning the game off then on again, I re-entered SCP-079's containment cell and the speech was properly delivered this time. So it would seem that this was only a side effect of the overloading phenomenon.