I worked on it on and off for several days, and spent three hours to finally find the problem.
There are many possible reasons for "token verification failed". Other netizens have almost exhausted them, but I haven't seen what I encountered on the Internet, so I will record it here.
The reason for failure is encoding problem;
Since I was developing in a project, I checked in order from business logic to technical logic, to domain name, registration, network, and coding.
Later I found that there is such a code include(../data.config.php) at the project entrance. In front of this code, echo $_GET['echostr'] can pass, but after this code, echo $_GET[ 'echostr'], it fails.
The original encoding format of the data.config.php file is (open with notepad++)
Adjust the format to The problem is solved.
In fact, utf-8 essentially has no difference between BOM and non-BOM. There will definitely be no misunderstanding during transmission, but there is nothing you can do about having two formats. I will explain in detail what a BOM is in another article.
Here is a hexadecimal comparison of different encodings.