Third party software [CRASH]

Here's what's been happening a few patches back and now(might have been here all the time, but there might not be any long games): My game keeps crashing. When the clock hits ~38 minutes(don't know for sure), it just crashes, and says it's because of there's a third party thingy and now I can just reconnect, and play my game. Well, of course, nothing too bad about that, except that after I reconnect, after exactly 3 minutes it happens again. And again. And again. Until the game is over. As I mostly play roles/champions that are vital for a team's success, it's just frustrating to lose the game because of something like this. In some cases in order to get back in the game I have to restart my whole computer, because Alt+Tab, Alt+F4, Task Manager just don't work and I can't get out of the game. I'd also like to say that I never installed a hack or anything of the sorts on my computer, not for any game. The only things running while I play League is League itself, TeamSpeak 3 and most of the time(but this doesn't seem to matter)my Windows Media Player. This bug always seems to happen when I reach ~38 minutes, and only after that, never in the earlier phases of the game. I have no idea how to reproduce the bug, as my friends don't seem to have this issue, and I'm really just clueless as to what's happening. (Accidentally posted it on Gameplay so I moved it here)

Edit 1: Just had this again, so I looked at the exact time it happens. This time it was 35:32, will try to get an exact time and some screeshots.

Edit 2: Couldn't recreate the bug in practice tool, so I'll wait for some more long games.

Edit 3: Couldn't recreate the bug in custom mode either, so I'm guessing it's only PvP games, 5v5.

Edit 4: The specs of my computer, might help someone somewhere: https://www.mediafire.com/file/fb44es97g29jj8h/Specs.rar/file

Edit 5: Ran the Hextech Repair tool, reinstalled the latest patch and searched for issues and corrupted game files but the issue still persists.

Edit 6: Ran several antivirus scans with different softwares, no issues found.