diff --git a/app/controllers/concerns/lti.rb b/app/controllers/concerns/lti.rb
index 0592b3da..30fb692e 100644
--- a/app/controllers/concerns/lti.rb
+++ b/app/controllers/concerns/lti.rb
@@ -170,8 +170,14 @@ module Lti
         # Reduce score by 100%
         normalized_lit_score *= 0.0
       end
-      response = provider.post_replace_result!(normalized_lit_score)
-      {code: response.response_code, message: response.post_response.body, status: response.code_major, score_sent: normalized_lit_score}
+
+      begin
+        response = provider.post_replace_result!(normalized_lit_score)
+        {code: response.response_code, message: response.post_response.body, status: response.code_major, score_sent: normalized_lit_score}
+      rescue IMS::LTI::XMLParseError
+        # A parsing error might happen if the LTI provider is down and doesn't return a valid XML response
+        {status: 'error'}
+      end
     else
       {status: 'unsupported'}
     end