Defender Scan keeps failing and is now stuck at 100%

Yesterday I installed defender and began my first scan. Two minutes in, it failed and showed the message: "Your server resource usage is too close to your limit. Please try again in 15 minutes." That I did. The scan page came up with 2% done now, and a couple of minutes later the same thing happened, it failed, and came up with the same error message. I continued to persevere. Every time it failed, I would retry the scan and it would show 2% more progress than when it had failed. And every time I restarted it, it would fail within 5 minutes. Eventually, after many retries, the scan reached 100%, this, I hoped would end it. However it is now stuck at 100%, loading for 5 minutes and then failing again.
My defender plugin now show 61 errors in my core, but if I click "fix" all it does it go to the error message, as above.
How can this problem be fixed?