diff --git a/checker/checker.go b/checker/checker.go
index 3b98cae..4a51817 100644
--- a/checker/checker.go
+++ b/checker/checker.go
@@ -219,6 +219,7 @@ func studentsChecker() {
 				}
 
 				dnsIP := stdIP
+				var glueErr error
 				// Is GLUE defined?
 				if glueIP, err := get_GLUE(std.MyDelegatedDomain()); glueIP != nil {
 					dnsIP = glueIP.String()
@@ -228,48 +229,59 @@ func studentsChecker() {
 					}
 				} else if err != nil {
 					log.Printf("%s and GLUE: %s\n", std.Login, err)
+					glueErr = err
 				}
 
 				// Check DNS
 				if addr, err := check_dns(std.MyDelegatedDomain(), dnsIP); err == nil {
-					if verbose {
-						log.Printf("%s just unlocked DNS challenge\n", std.Login)
-					}
-					if _, err := std.UnlockChallenge(100*(tunnel_version-1)+3, ""); err != nil {
-						log.Printf("Unable to register challenge for %s: %s\n", std.Login, err.Error())
-					}
-
-					// Check HTTP with DNS
 					if addr == nil {
-						log.Printf("%s and HTTP (with DNS ip=%s): skipped due to empty response\n", std.Login, addr.String())
-					} else if err := check_http(addr.String(), std.MyDelegatedDomain()); err == nil {
-						if verbose {
-							log.Printf("%s just unlocked HTTP challenge\n", std.Login)
+						dnsAt := " at " + dnsIP
+						if glueErr != nil {
+							dnsAt = " + there is a problem with the GLUE record: " + glueErr.Error()
 						}
-						if _, err := std.UnlockChallenge(100*(tunnel_version-1)+4, ""); err != nil {
-							log.Printf("Unable to register challenge for %s: %s\n", std.Login, err.Error())
+						if errreg := std.RegisterChallengeError(100*(tunnel_version-1)+3, fmt.Errorf("%s: empty response from the server%s", std.MyDelegatedDomain(), dnsAt)); errreg != nil {
+							log.Printf("Unable to register challenge error for %s: %s\n", std.Login, errreg)
 						}
 					} else {
-						std.RegisterChallengeError(100*(tunnel_version-1)+4, err)
 						if verbose {
-							log.Printf("%s and HTTP (with DNS ip=%s): %s\n", std.Login, addr.String(), err)
+							log.Printf("%s just unlocked DNS challenge\n", std.Login)
 						}
-					}
-
-					// Check HTTPs with DNS
-					if addr == nil {
-						log.Printf("%s and HTTPS (with DNS ip=%s): skipped due to empty response\n", std.Login, addr.String())
-					} else if err := check_https(std.MyDelegatedDomain(), addr.String()); err == nil {
-						if verbose {
-							log.Printf("%s just unlocked HTTPS challenge\n", std.Login)
-						}
-						if _, err := std.UnlockChallenge(100*(tunnel_version-1)+5, ""); err != nil {
+						if _, err := std.UnlockChallenge(100*(tunnel_version-1)+3, addr.String()); err != nil {
 							log.Printf("Unable to register challenge for %s: %s\n", std.Login, err.Error())
 						}
-					} else {
-						std.RegisterChallengeError(100*(tunnel_version-1)+5, err)
-						if verbose {
-							log.Printf("%s and HTTPS (with DNS ip=%s): %s\n", std.Login, addr.String(), err)
+
+						// Check HTTP with DNS
+						if glueErr != nil {
+							std.RegisterChallengeError(100*(tunnel_version-1)+4, fmt.Errorf("Unable to perform the test due to GLUE problem: %w", err))
+						} else if err := check_http(addr.String(), std.MyDelegatedDomain()); err == nil {
+							if verbose {
+								log.Printf("%s just unlocked HTTP challenge\n", std.Login)
+							}
+							if _, err := std.UnlockChallenge(100*(tunnel_version-1)+4, ""); err != nil {
+								log.Printf("Unable to register challenge for %s: %s\n", std.Login, err.Error())
+							}
+						} else {
+							std.RegisterChallengeError(100*(tunnel_version-1)+4, err)
+							if verbose {
+								log.Printf("%s and HTTP (with DNS ip=%s): %s\n", std.Login, addr.String(), err)
+							}
+						}
+
+						// Check HTTPs with DNS
+						if glueErr != nil {
+							std.RegisterChallengeError(100*(tunnel_version-1)+5, fmt.Errorf("Unable to perform the test due to GLUE problem: %w", err))
+						} else if err := check_https(std.MyDelegatedDomain(), addr.String()); err == nil {
+							if verbose {
+								log.Printf("%s just unlocked HTTPS challenge\n", std.Login)
+							}
+							if _, err := std.UnlockChallenge(100*(tunnel_version-1)+5, ""); err != nil {
+								log.Printf("Unable to register challenge for %s: %s\n", std.Login, err.Error())
+							}
+						} else {
+							std.RegisterChallengeError(100*(tunnel_version-1)+5, err)
+							if verbose {
+								log.Printf("%s and HTTPS (with DNS ip=%s): %s\n", std.Login, addr.String(), err)
+							}
 						}
 					}
 				} else {