After publishing your ASP.NET Core application to the server, you may run into errors.  You can start troubleshooting the problem by enabling error logging in your web.config file.  A common misconception is that there is no web.config file because you don't see one in your Visual Studio project.  The file is actually created when you publish.  To enable error logging:

  1. FTP into your account using an FTP program like FileZilla.
  2. Download the web.config file from the server.
  3. Open it locally using a text editor like Notepad.
  4. Change the stdoutLogEnabled attribute from "false" to "true".
  5. Save the file.
  6. Reupload the modified web.config file to the server, overwriting it.
  7. Create a "logs" folder in the same directory where you published your ASP.NET Core application.  If you prefer, you can change the location where the logs are saved.  Just modify the stdoutLogFile attribute's path in the web.config file and then create the corresponding folder where you want the logs placed in.
A sample web.config file can be found below:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <location path="." inheritInChildApplications="false">
    <system.webServer>
      <handlers>
        <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" resourceType="Unspecified" />
      </handlers>
      <aspNetCore processPath=".\NET5.0.6.exe" stdoutLogEnabled="true" stdoutLogFile=".\logs\stdout" hostingModel="inprocess" />
    </system.webServer>
  </location>
</configuration>