Common webpage errors 400/401/403/404/500 the meaning of the webpage error code

HTTP Error 400
400 request Error
The server cannot understand the request because of incorrect syntax format. If no modification is made, the client program cannot repeat the request.
HTTP error 401
401.1 unauthorized: Logon Failed
This error indicates that the certificate transmitted to the server does not match the certificate required to log on to the server.
Contact the Web server administrator to check whether you have the permission to access the requested resources.
401.2 unauthorized: Login Failed due to server configuration
This error indicates that the certificate transmitted to the server does not match the certificate required to log on to the server. This error is usually caused by the failure to send the correct WWW verification header field.
Contact the Web server administrator to check whether you have the permission to access the requested resources.
401.3 unauthorized: unauthorized due to the ACL in the Resource
This error indicates that the certificate transmitted by the customer does not have access to specific resources on the server. This resource may be a webpage or file listed in the client's address line, or other files on the server required to process the files listed in the client's address line.
Record the full address of the attempt and contact the Web server administrator to check whether you have the permission to access the requested resources.
401.4 unauthorized: the authorized service is rejected by the screening program.
This error indicates that the Web server has installed a filter program to verify the user connected to the server. This filter rejects access to the genuine certificate that is connected to this server.
Record the full address of the attempt and contact the Web server administrator to check whether you have the permission to access the requested resources.
401.5 unauthorized: Authorization for ISAPI/CGI applications failed
This error indicates that an ISAPI or CGI program has been installed on the address of the Web server to be used to verify the user's certificate before continuing. This program rejects access to the genuine certificate used to connect to the server.
Record the full address of the attempt and contact the Web server administrator to check whether you have the permission to access the requested resource.
HTTP Error 403
403.1 forbidden: Access prohibited
This error may occur if you execute CGI, ISAPI, or other execution programs from directories that are not allowed to execute programs.
If the problem persists, contact the Web server administrator.
403.2 forbidden: Access prohibited
This error occurs if no default web page is available or directory browsing is not enabled, or if you attempt to display HTML pages residing in a directory marked only as execution or script permission.
If the problem persists, contact the Web server administrator.
403.3 forbidden: Write access is prohibited.
This problem occurs if you try to upload or modify files in directories that do not allow write access.
If the problem persists, contact the Web server administrator.
403.4 forbidden: SSL required
This error indicates that the webpage to be accessed is protected by SSL. To view the IP address, you must enter https: // before accessing the address to enable SSL.
If the problem persists, contact the Web server administrator.
403.5 forbidden: SSL 128 is required
This error message indicates that the resource you are trying to access is protected by 128-bit Secure Sockets Layer (SSL. To view this resource, you must have a browser that supports this SSL layer.
Check whether the browser supports 128-bit SSL security. If yes, contact the Web server administrator and report the problem.
403.6 forbidden: reject IP addresses
If the server contains a list of IP addresses that are not allowed to access the site and you are using an IP address in this list, this problem occurs.
If the problem persists, contact the Web server administrator.
403.7 forbidden: user certificate required
This problem occurs when the attempt to access resources requires the browser to have a server-recognizable user Security Socket Layer (SSL) certificate. It can be used to verify whether you are a legal user of this resource.
Contact the Web server administrator to obtain a valid user certificate.
403.8 forbidden: site access prohibited
This problem occurs if the Web server does not provide services for requests or you do not have the permission to connect to the site.
Contact the Web server administrator.
403.9 Access prohibited: too many connected users
This problem occurs when the Web is too busy and your request cannot be processed due to excessive traffic. Connect again later.
If the problem persists, contact the Web server administrator.
403.10 Access prohibited: Invalid Configuration
The configuration of the Web server is faulty.
If the problem persists, contact the Web server administrator.
403.11 Access prohibited: the password has been changed
This error occurs if the user enters an incorrect password during authentication. Refresh the webpage and try again.
If the problem persists, contact the Web server administrator.
403.12 Access prohibited: The ing program rejects access
Deny user certificate attempts to access this Web site.
Contact the site administrator to create user certificate permissions. If necessary, you can also change the user certificate and try again.
HTTP Error 404
404 cannot be found
The Web server cannot find the file or script you requested. Check the URL to ensure that the path is correct.
If the problem persists, contact the server administrator.
HTTP Error 405
405 this method is not allowed.
The method specified in the request line is not allowed for the resource identified by the request. Make sure that the correct MIME type is set for the requested resource.
If the problem persists, contact the server administrator.
HTTP Error 406
406 unacceptable
Based on the "accept" title sent in this request, the resource identified by this request can only generate response entities whose content features are "unacceptable.
If the problem persists, contact the server administrator.
HTTP Error 407
407 proxy authentication required
You must verify the proxy server before providing services for this request. Log on to the proxy server and try again.
If the problem persists, contact the Web server administrator.
HTTP Error 412
412 precondition failed
When you test the prerequisite on the server, the precondition given in some request header fields is estimated to be FALSE. The client places the prerequisites in the current resource metainformation to prevent the requested method from being misused to other resources.
If the problem persists, contact the Web server administrator.
HTTP Error 414
414 Request-URI is too long
The Request-URL is too long and the server rejects the Request. This condition is only possible under the following conditions:
The client mistakenly converts a POST request to a GET request with long query information.
The customer has the opportunity to redirect (for example, the redirection prefix pointing to its own suffix ).
The server is being disturbed by customers attempting to exploit security vulnerabilities in some servers (using a fixed-length buffer for reading or executing Request-URI.
If the problem persists, contact the Web server administrator.
HTTP Error 500
500 Internal Server Error
The Web server cannot execute this request. Please try again later.
If the problem persists, contact the Web server administrator.
HTTP Error 501
501 not implemented
The Web server does not support the functions required to implement this request. Check the URL for errors. If the problem persists, contact the Web server administrator.
HTTP Error 502
502 A Gateway error occurred.
When used as a gateway or proxy, the server will receive invalid responses from the upstream server accessed when trying to implement this request.
If the problem persists, contact the Web server administrator.