The computer shut down when installing the game

Installed Dark souls 3 and at the end the system just shut down. Turned back on after 2 minutes. Thermal paste i changed a week ago, before that i used to get 88-90(Days Gone) hot in games, max 65.

razen 2600 overclocked to 3.9 (now it is 3.7)
memory 16g 3000mgz (now 2660)
1660s
First time in 3 years, even the wine from the purchase stands.
What could it be and is it worth worrying?