508 Loop Detected

That sounds like it could be a server configuration issue, and I can’t reproduce it on my own site (it marks the example links as working).

Try clicking on the error message in the “Status” column. This will display more information about the error. What does the “Log” field say?

from Status:

=== HTTP code : 508 ===
HTTP/1.1 508 Loop Detected
Date: Mon, 19 Jan 2015 14:06:54 GMT
Server: Apache
Content-Length: 455
Connection: close
Content-Type: text/html

from Log:
DEBUG: blcLink:save Updating a link. SQL query:
‘UPDATE wpx_blc_links SET url = \’https://astrobene.ru/subscription\’, first_failure = \’2015-01-19 13:02:13\’, last_check = \’2015-01-19 13:33:01\’, last_success = \’0000-00-00 00:00:00\’, last_check_attempt = \’2015-01-19 14:06:23\’, check_count = 3, final_url = \’https://astrobene.ru/subscription\’, redirect_count = 0, log = \’=== HTTP code : 508 ===\\n\\nHTTP/1.1 508 Loop Detected\\r\\nDate: Mon, 19 Jan 2015 13:33:06 GMT\\r\\nServer: Apache\\r\\nContent-Length: 455\\r\\nConnection: close\\r\\nContent-Type: text/html\\r\\n\\r\\n\\nСсылка не работает.\’, http_code = 508, request_duration = 0.002277, timeout = 0, result_hash = \’508|broken|0|https://astrobene.ru/subscription\’, broken = 1, warning = 0, false_positive = 0, may_recheck = 1, being_checked = 1, status_text = \’\’, status_code = \’\’, dismissed = 0 WHERE link_id=29′

DEBUG: blcLink:save Link updated.

DEBUG: HTTP module checking “https://astrobene.ru/subscription”
[2015-01-19 14:06:25 +00:00] INFO: blcCurlHttp Checking link ‘https://astrobene.ru/subscription’

DEBUG: blcCurlHttp Clean URL: ‘https://astrobene.ru/subscription’

DEBUG: HTTP request took 0.002 seconds
[2015-01-19 14:06:25 +00:00] INFO: HTTP response: 508, duration: 0.00 seconds, status text: “N/A”

INFO: blcCurlHttp Checking link ‘https://astrobene.ru/subscription’

DEBUG: blcCurlHttp Clean URL: ‘https://astrobene.ru/subscription’

DEBUG: HTTP request took 0.002 seconds

INFO: HTTP response: 508, duration: 0.00 seconds, status text: “N/A”

DEBUG: blcLink:save Updating a link. SQL query:
‘UPDATE wpx_blc_links SET url = \’https://astrobene.ru/subscription\’, first_failure = \’2015-01-19 13:02:13\’, last_check = \’2015-01-19 14:06:23\’, last_success = \’0000-00-00 00:00:00\’, last_check_attempt = \’2015-01-19 14:06:23\’, check_count = 3, final_url = \’https://astrobene.ru/subscription\’, redirect_count = 0, log = \’=== HTTP code : 508 ===\\n\\nHTTP/1.1 508 Loop Detected\\r\\nDate: Mon, 19 Jan 2015 14:06:25 GMT\\r\\nServer: Apache\\r\\nContent-Length: 455\\r\\nConnection: close\\r\\nContent-Type: text/html\\r\\n\\r\\n\\nСсылка не работает.\’, http_code = 508, request_duration = 0.001518, timeout = 0, result_hash = \’508|broken|0|https://astrobene.ru/subscription\’, broken = 1, warning = 0, false_positive = 0, may_recheck = 1, being_checked = 0, status_text = \’\’, status_code = \’\’, dismissed = 0 WHERE link_id=29′

DEBUG: blcLink:save Link updated.

Unfortunately, the HTTP headers and the log don’t really provide any clues as to what might have caused the error. I was hoping that the headers would show a redirect loop or something like that, but they don’t.

It still sounds like a server-side issue of some sort. Just a guess: Perhaps loopback connections aren’t set up correctly? Or maybe the server tries to redirect or block certain IPs?