Error 0xc000021a, on a dual boot system, one hard drive. any fixes?

[Guest vq.]

Ive had two systems installed, 2 different versions of windows one is purely just for games, it is windows 8.1 which im aware that is out of support. And my main = win 10. I've had no errors until now. When this error happened:I was on windows 8.1. It has 1 partition (out of the 3 total on my harddrive). I went into another partition, which I've been using before to store some files on while using windows 10.My win 10 were in 2 partitions: 1. System files etc, the partition with windows, and 2. downloads and etc, just files that i use. I made a 3rd partition, purely for win 8.1, for some games

 

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