--- a/OrthancServer/Sources/OrthancInitialization.cpp	Wed Mar 16 09:50:33 2022 +0100
+++ b/OrthancServer/Sources/OrthancInitialization.cpp	Thu Mar 17 17:03:59 2022 +0100
@@ -252,8 +252,24 @@
         {
           const std::string& tagName = content[t].asString();
           DicomTag tag(FromDcmtkBridge::ParseTag(tagName));
-          DicomMap::AddMainDicomTag(tag, tagName, level);
-          LOG(INFO) << "  - " << tagName;
+
+          if (DicomMap::IsComputedTag(tag))
+          {
+            LOG(WARNING) << "  - " << tagName << " can not be added in the Extra Main Dicom Tags since the value of this tag is computed when requested";
+          }
+          else
+          {
+            ValueRepresentation vr = FromDcmtkBridge::LookupValueRepresentation(tag);
+            if (vr == ValueRepresentation_Sequence)
+            {
+              LOG(WARNING) << "  - " << tagName << " can not be added in the Extra Main Dicom Tags since it is a sequence";
+            }
+            else
+            {
+              DicomMap::AddMainDicomTag(tag, tagName, level);
+              LOG(INFO) << "  - " << tagName;
+            }
+          }
         }
       }
     }
@@ -357,6 +373,8 @@
     LoadExternalDictionaries(lock.GetJson());  // New in Orthanc 1.9.4
     LoadCustomDictionary(lock.GetJson());
 
+    lock.GetConfiguration().LoadWarnings();
+
     LoadMainDicomTags(lock.GetJson());  // New in Orthanc 1.11.0
 
     lock.GetConfiguration().RegisterFont(ServerResources::FONT_UBUNTU_MONO_BOLD_16);