Keil MDK solves the problem of “error: encoded an improved argument”

Arm official problem description and solutions: https://developer.arm.com/documentation/ka004382/latest

Cause of problem: μ The vision5 debugger is currently unable to process dwarf debugging information that contains folders or file names with UTF-8 characters. In other words, your project directory should be in Chinese, instead of using the directory with Chinese.

Solution: change all the paths to English, then clean up the project and recompile.