ACCESS_DENIED - Access to this location is not authorized
page title contains 'not authorized' or 'Central Authentication Service'
link is an external file that gives an unauthorized code
ANCHOR_INVALID - Anchor is invalid
link is an anchor (with hash) and no id, name, or ng-href elements were found to match what the anchor is referencing
CAS_REDIRECT - URL redirected to CAS
no code uses this error
FILE_NOT_FOUND - URL refers to a non-existent resource
link is internal and an XML HTTP Request did not return code 200
link is external and a NET HTTP Request gave no response
INVALID_URL - Invalid URL format
A part or multiple parts of the URL (anchor, URI, host, port, extension, and/or query) is invalid
INVALID_URL_TOKEN - Course ID is missing or invalid
URL is internal but does not contain the course ID/token in the URL or as an “ou” or “orgunitid” parameter in the query and does not satisfy any NO_TOKEN rules
MULTIPLE_URL_TOKENS - URL contains multiple course IDs
URL is internal and the course ID/token appears multiple times in the URL or as an “ou” or “orgunitid” parameter in the query
PAGE_NOT_FOUND - Page not found
Page contains ‘<html><head></head><body></body></html>’ somewhere in the html source
Page title contains any of the following: 'not found', 'failed to load', 'not available', 'cannot be found', 'offline', '404', '500'
A text element in the page body contains the 'The file associated with this content topic cannot be found.'
Page/URL is external and cannot be reached using Net HTTP request or Selenium
There is a Socket Error (usually means cannot resolve hostname) anytime during the URL processing
SELENIUM_ERROR - Page not loaded due to an internal browser error
the browser the app uses to process URLs/Pages could not be created or connected
URL_REDIRECT_ERROR - Too many redirects
the URL is external and Net HTTP request returned a HTTP redirect response
URL_SSL_ERROR - URL could not be checked due to an SSL error
App may have outdated SSL certificate files
URL_TIMEOUT - URL could not be checked due to a timeout error
Something times out at any point in the URL processing
PHANTOMJS_ERROR - Page not loaded due to an internal driver error
There is an error with PhantomJS, the headless browser used to visit the URLs
UNKNOWN_EXCEPTION - URL could not be checked due to an unknown error
Process was interrupted with an error but was not identified as any of the above errors
If none of these errors are flagged, then the URL is ValidOn the My searches tab, if you click on a search and go to the Rules section, you can find the different types of rules each link follows, and the number of links of each type of rule. If the search finds a link with the value in the URL, it will check based on the type of rule it is
...
There are 4 types of Rules:
NO_FOLLOW:
When this rule is applied, links are completely ignored, and none of the checks are invoked. Essentially, Link Checker does not follow or validate these links. It's impossible to determine if these links are valid or functional.
NO_SCAN:
With the NO_SCAN rule, links are still processed as usual, but the pages they point to are treated as external pages. This means that the content of these external pages is not scanned for links. However, the links themselves are still processed and validated.
NO_TOKEN:
Links that meet this rule criteria are not required to have a course ID in the URL to be processed. In other words, Link Checker will still validate and process these links even if they don't contain a course ID parameter in their URL structure.
SCRIPT:
This rule applies to non-HTML and non-file links that cannot be validated or followed. Examples include JavaScript links or links to executable files. Link Checker recognizes these links but does not attempt to validate or follow them due to their non-standard nature.