diff --git a/PhysicsAnalysis/CommonTools/ExpressionEvaluation/Root/MultipleProxyLoader.cxx b/PhysicsAnalysis/CommonTools/ExpressionEvaluation/Root/MultipleProxyLoader.cxx
index cb19074937af21cb6d8dd087654a9fcf8a8b0cda..cdd8dcadf6ca6b79fc98f5d8a3eb920ef8aac93d 100644
--- a/PhysicsAnalysis/CommonTools/ExpressionEvaluation/Root/MultipleProxyLoader.cxx
+++ b/PhysicsAnalysis/CommonTools/ExpressionEvaluation/Root/MultipleProxyLoader.cxx
@@ -14,6 +14,7 @@
 
 #include <stdexcept>
 #include <iostream>
+#include <sstream>
 
 namespace ExpressionParsing {
   MultipleProxyLoader::MultipleProxyLoader() :
@@ -56,8 +57,16 @@ namespace ExpressionParsing {
       m_varnameToProxyLoader.emplace(varname, proxyLoader);
       return result;
     }
-
-    throw std::runtime_error("MultipleProxyLoader: unable to find valid proxy loader for "+varname);
+    std::stringstream msg;
+    msg << "MultipleProxyLoader: unable to find valid proxy loader for " << varname << "."
+        << " If it is an xAOD element or container which is read from the input file"
+        << " this problem may occur if it is not accessed anywhere in the job via read handles."
+        << " The problem can be mitigated by providing the missing information in the property "
+        << " ExtraDataForDynamicConsumers of the sequence which has the property "
+        << " ProcessDynamicDataDependencies set to True."
+        << " The property takes a list of strings of the form \'type/container-name\' e.g."
+        << " \'xAOD::TrackParticleContainer/InDetTrackParticles\'.";
+    throw std::runtime_error(msg.str());
   }
 
   int MultipleProxyLoader::loadIntVariableFromString(const std::string &varname) const
diff --git a/PhysicsAnalysis/CommonTools/ExpressionEvaluation/src/SGxAODProxyLoader.cxx b/PhysicsAnalysis/CommonTools/ExpressionEvaluation/src/SGxAODProxyLoader.cxx
index 63e34fe5de9cfd309b873610abd32bde10a0a74a..817de5bc74ebca192fd67a95035e34b9b756ddf9 100644
--- a/PhysicsAnalysis/CommonTools/ExpressionEvaluation/src/SGxAODProxyLoader.cxx
+++ b/PhysicsAnalysis/CommonTools/ExpressionEvaluation/src/SGxAODProxyLoader.cxx
@@ -319,7 +319,16 @@ namespace ExpressionParsing {
            const SG::BaseInfoBase* base_info = (container_data_id ? SG::BaseInfoBase::find (container_data_id->clid()) : nullptr);
            if (!base_info) {
               std::stringstream msg;
-              msg << "Missing type information about container  " << container_name << ".";
+              msg << "Missing type information about container " << container_name << ".";
+              if (container_data_id) {
+                 msg << " It seems that inheritance information is missing for " << container_data_id->className() << "."
+                     << " Only container which inherit from SG::AuxVectorBase or data inheriting from  SG::AuxElement "
+                     << " are supported by the SGxAODProxyLoader loader.";
+              }
+              else {
+                  msg << " This problem may occur if the container is read from the input"
+                      << " file and not accessed anywhere in the job via read handles. ";
+              }
               throw std::runtime_error(msg.str());
            }
            // ---DEBUG