How to view detailed error information after "Unknown error" or "Unknown error" is reported on the page during SharePoint Development

In SharePoint development, applications often appear when we browse pages.ProgramExceptions (of course, these exceptions are not handled by ourselves, and errors are generated when the program is compiled and executed). At this time, only the error message is displayed on the page: "Unknown error" or "Unknown error", it is difficult to find the error source for this exception information, so we hope to see more accurate error information. So how can we see detailed error information? The method is as follows:

1. Open the application directory, which is in "C: \ Inetpub \ wwwroot \ WSS \ virtualdirectories" by default;

2. Find the "Web. config" file and open it (make sure to back up the file before modification to prevent the original version from being restored after misoperation );

3. Find <safemode maxcontrols = "200" callstack = "true "...... /> Change to <safemode maxcontrols = "200" callstack = "true "..... />;

4. Change <customerrors mode = "on"/> to <customerrors mode = "off"/>.

5. Save the Web. config file.

6. view the program at this time. If any exception occurs, more detailed information will be displayed.