What should I do if the Flash Loader Demonstrator does not respond?

First of all, look at whether the errors are the same.

Solution:
Step 1:
Unplug the download cable of the pocket machine. Both the pocket and the computer terminal must be unplugged (there is a picture of the download cable of the pocket terminal below, and the computer terminal must be unplugged if it is not taken).

Step 2:
Turn off the power of stm32.

Step 3: The
last and most important step:
Press and hold the button in the yellow circle until all the small white lights around are lit. (Friendly tips: 1. Just long press the button once and don't press it too much. 2. Finally reopen the Flash Loader software. You can try more, mainly around that button).

I forgot to take the screenshot of the last successful screenshot (because I did it in the lab), but I can definitely try it myself, otherwise I will not blog. This problem is really messy, and the online solutions are the same, not very understandable, but I was lucky to try it out by myself, I hope it can help you.