Connection test results (HTTP Status Codes)

Reference guide for HTTP status codes returned by MainWP connection tests. Covers 2xx success codes, 3xx redirections, 4xx client errors like 403 and 404, and 5xx server errors to help diagnose connection issues.

When you run a connection test in MainWP, the result includes an HTTP status code that indicates whether the request succeeded or failed. This reference helps you interpret those codes and understand what action to take.

What You’ll Learn

• Interpret HTTP status codes from connection tests
• Identify which codes indicate success vs. failure
• Understand common causes for specific error codes
• Determine next steps based on the status code

Prerequisites

• MainWP Dashboard installed and activated
• A child site you’re testing connection to

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How to Run a Connection Test

Go to MainWP > Sites > Manage Sites, find the site, and click Test Connection from the site’s action menu. The result displays the HTTP status code returned by the child site server.

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2xx – Success Codes

These codes indicate the request was received and processed successfully.

Code	Status	Description
200	OK	Standard response for successful HTTP requests
201	Created	Request has been fulfilled; new resource created
202	Accepted	Request accepted, processing pending. Note: On SiteGround, this may indicate a captcha challenge blocking MainWP
203	Non-Authoritative Information	Request processed, information may be from another source
204	No Content	Request processed, no content returned
205	Reset Content	Request processed, no content returned, reset the document view
206	Partial Content	Partial resource return due to the request header
207	Multi-Status	XML can contain multiple separate responses
208	Already Reported	Results previously returned
226	IM Used	Request fulfilled, the response is instance-manipulations

200 OK is the expected result for a successful connection test.

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3xx – Redirection Codes

These codes indicate the request was redirected to another location.

Code	Status	Description
300	Multiple Choices	Multiple options for the resource delivered
301	Moved Permanently	This and all future requests directed to the given URI
302	Found	Temporary response to request found via alternative URI
303	See Other	Permanent response to request found via alternative URI
304	Not Modified	Resource has not been modified since last requested
305	Use Proxy	Content located elsewhere, retrieve from there
306	Reserved	Subsequent requests should use the specified proxy
307	Temporary Redirect	Connect again to different URI as provided
308	Permanent Redirect	Resumable HTTP requests

Common cause: The child site URL has changed (HTTP to HTTPS, www to non-www, or domain change). Update the site URL in MainWP to match the current address.

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4xx – Client Error Codes

These codes indicate the request failed due to a client-side issue.

Code	Status	Description
400	Bad Request	Request cannot be fulfilled due to bad syntax
401	Unauthorized	Authentication is possible but has failed
402	Payment Required	Payment required, reserved for future use
403	Forbidden	Server refuses to respond to the request
404	Not Found	Requested resource could not be found
405	Method Not Allowed	Request method not supported by that resource
406	Not Acceptable	Content not acceptable according to the Accept headers
407	Proxy Authentication Required	Client must first authenticate itself with the proxy
408	Request Timeout	Server timed out waiting for the request
409	Conflict	Request could not be processed because of conflict
410	Gone	Resource is no longer available and will not be available again
411	Length Required	Request did not specify the length of its content
412	Precondition Failed	Server does not meet request preconditions
413	Request Entity Too Large	Request is larger than the server is willing or able to process
414	Request-URI Too Long	URI provided was too long for the server to process
415	Unsupported Media Type	Server does not support the media type
416	Requested Range Not Satisfiable	The client has asked for unprovable portion of the file
417	Expectation Failed	Server cannot meet requirements of Expect request-header field
422	Unprocessable Entity	Request unable to be followed due to semantic errors
423	Locked	Resource that is being accessed is locked
424	Failed Dependency	Resource that is being accessed is locked
426	Upgrade Required	Client should switch to a different protocol
428	Precondition Required	Origin server requires the request to be conditional
429	Too Many Requests	User has sent too many requests in a given amount of time
431	Request Header Fields Too Large	Server is unwilling to process the request

Common 4xx Codes in MainWP

Code	Likely Cause	Action
403	Firewall blocking the request	Whitelist your Dashboard IP in the child site’s firewall
404	MainWP Child plugin not installed or deactivated	Install and activate MainWP Child on the child site
415	ModSecurity or Imunify360 blocking the request	Add exclusion rule for your Dashboard IP
429	Rate limiting by host or security plugin	Wait and retry, or whitelist your Dashboard IP

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5xx – Server Error Codes

These codes indicate the request failed due to a server-side issue on the child site.

Code	Status	Description
500	Internal Server Error	Generic error message
501	Not Implemented	Server does not recognize the method or lacks the ability to fulfill
502	Bad Gateway	Server received an invalid response from the upstream server
503	Service Unavailable	Server is currently unavailable
504	Gateway Timeout	Gateway did not receive a response from the upstream server
505	HTTP Version Not Supported	Server does not support the HTTP protocol version
506	Variant Also Negotiates	Content negotiation for the request results in a circular reference
507	Insufficient Storage	Server is unable to store the representation
508	Loop Detected	Server detected an infinite loop while processing the request
509	Bandwidth Limit Exceeded	Hosting bandwidth limit reached
510	Not Extended	Further extensions to the request are required
511	Network Authentication Required	Client needs to authenticate to gain network access

Common 5xx Codes in MainWP

Code	Likely Cause	Action
500	PHP error on child site	Enable error logging and check the debug.log file
502	Proxy or load balancer issue	Contact hosting support
503	Server overloaded or in maintenance	Wait and retry, or contact hosting support
504	Request took too long	Increase PHP timeout limits or contact hosting support

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Self-Check Checklist

• Ran connection test and noted the status code
• Identified whether the code indicates success (2xx) or error (4xx/5xx)
• Reviewed common causes for the specific code
• Took appropriate action based on the code meaning

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Related Resources

• Troubleshoot Connection Problems - Resolve common connection issues
• How to Enable Error Logging - Debug 500 errors
• Force Reconnection - Re-establish connections