diff --git a/FWCore/Catalog/src/FileLocator.cc b/FWCore/Catalog/src/FileLocator.cc
index ca7e3ea7ea94e..b22acebe754eb 100644
--- a/FWCore/Catalog/src/FileLocator.cc
+++ b/FWCore/Catalog/src/FileLocator.cc
@@ -268,8 +268,8 @@ namespace edm {
     //let enforce that site-local-config.xml and storage.json contains valid catalogs in <data-access>, in which site defined in site-local-config.xml <data-access> should be found in storage.json
     if (found_site == json.end()) {
       cms::Exception ex("FileCatalog");
-      ex << "Can not find site and volume " << aCatalog.site << ", " << aCatalog.volume << " in " << filename_storage
-         << ". Check site-local-config.xml <data-access> and storage.json";
+      ex << "Can not find storage site \"" << aCatalog.storageSite << "\" and volume \"" << aCatalog.volume
+         << "\" in storage.json. Check site-local-config.xml <data-access> and storage.json";
       ex.addContext("edm::FileLocator:init()");
       throw ex;
     }
@@ -283,8 +283,9 @@ namespace edm {
     //let enforce that site-local-config.xml and storage.json contains valid catalogs, in which protocol defined in site-local-config.xml <data-access> should be found in storage.json
     if (found_protocol == protocols.end()) {
       cms::Exception ex("FileCatalog");
-      ex << "Can not find protocol " << aCatalog.protocol
-         << " in storage.json. Check site-local-config.xml <data-access> and storage.json";
+      ex << "Can not find protocol \"" << aCatalog.protocol << "\" for the storage site \"" << aCatalog.storageSite
+         << "\" and volume \"" << aCatalog.volume
+         << "\" in storage.json. Check site-local-config.xml <data-access> and storage.json";
       ex.addContext("edm::FileLocator:init()");
       throw ex;
     }
diff --git a/FWCore/Catalog/src/InputFileCatalog.cc b/FWCore/Catalog/src/InputFileCatalog.cc
index 26b51d7504240..cbbc9d7e08029 100644
--- a/FWCore/Catalog/src/InputFileCatalog.cc
+++ b/FWCore/Catalog/src/InputFileCatalog.cc
@@ -9,6 +9,7 @@
 
 #include "FWCore/Utilities/interface/Exception.h"
 #include "FWCore/Utilities/interface/EDMException.h"
+#include "FWCore/MessageLogger/interface/MessageLogger.h"
 
 #include <boost/algorithm/string.hpp>
 
@@ -57,7 +58,11 @@ namespace edm {
         }
 
         edm::CatalogAttributes inputOverride_struct(
-            tmps[0], tmps[1], tmps[2], tmps[3], tmps[4]);  //site, subSite,storageSite,volume,protocol
+            tmps[0],
+            tmps[1],
+            tmps[2],
+            tmps[3],
+            tmps[4]);  //current-site,current-subSite,desired-data-access-site,desired-data-access-volume,desired-data-access-protocol
 
         overrideFileLocator_ =
             std::make_unique<FileLocator>(inputOverride_struct);  // propagate_const<T> has no reset() function
@@ -76,28 +81,44 @@ namespace edm {
       std::vector<std::string> const& tmp_dataCatalogs = localconfservice->trivialDataCatalogs();
       if (!fileLocators_trivalCatalog_.empty())
         fileLocators_trivalCatalog_.clear();
-
-      //require the first file locator to success so obvious mistakes in data catalogs, typos for example, can be catched early. Note that tmp_dataCatalogs is not empty at this point. The protection is done inside the trivialDataCatalogs() of SiteLocalConfigService
-      fileLocators_trivalCatalog_.push_back(std::make_unique<FileLocator>(tmp_dataCatalogs.front()));
-
-      for (auto it = tmp_dataCatalogs.begin() + 1; it != tmp_dataCatalogs.end(); ++it) {
+      //Construct all file locators from data catalogs. If a data catalog is invalid (wrong protocol for example), it is skipped and no file locator is constructed (an exception is thrown out from FileLocator::init).
+      for (auto it = tmp_dataCatalogs.begin(); it != tmp_dataCatalogs.end(); ++it) {
         try {
           fileLocators_trivalCatalog_.push_back(std::make_unique<FileLocator>(*it));
         } catch (cms::Exception const& e) {
-          continue;
+          edm::LogWarning("InputFileCatalog")
+              << "Catch an exception while constructing a file locator in InputFileCatalog::init: " << e.what();
+          if (it != tmp_dataCatalogs.end() - 1) {
+            std::cout << "\n Skip this catalog" << std::endl;
+            continue;
+          } else {
+            cms::Exception ex("FileCatalog");
+            ex << "Can not construct a file locator in InputFileCatalog::init";
+            ex.addContext("Calling edm::InputFileCatalog::init()");
+            throw ex;
+          }
         }
       }
     } else if (catType == edm::CatalogType::RucioCatalog) {
       std::vector<edm::CatalogAttributes> const& tmp_dataCatalogs = localconfservice->dataCatalogs();
       if (!fileLocators_.empty())
         fileLocators_.clear();
-      //require the first file locator to success so obvious mistakes in data catalogs, typos for example, can be catched early. Note that tmp_dataCatalogs is not empty at this point. The protection is done inside the dataCatalogs() of SiteLocalConfigService
-      fileLocators_.push_back(std::make_unique<FileLocator>(tmp_dataCatalogs.front()));
-      for (auto it = tmp_dataCatalogs.begin() + 1; it != tmp_dataCatalogs.end(); ++it) {
+      //Construct all file locators from data catalogs. If a data catalog is invalid (wrong protocol for example), it is skipped and no file locator is constructed (an exception is thrown out from FileLocator::init).
+      for (auto it = tmp_dataCatalogs.begin(); it != tmp_dataCatalogs.end(); ++it) {
         try {
           fileLocators_.push_back(std::make_unique<FileLocator>(*it));
         } catch (cms::Exception const& e) {
-          continue;
+          edm::LogWarning("InputFileCatalog")
+              << "Catch an exception while constructing a file locator in InputFileCatalog::init: " << e.what()
+              << "Skip this catalog";
+          if (it != tmp_dataCatalogs.end() - 1) {
+            continue;
+          } else {
+            cms::Exception ex("FileCatalog");
+            ex << "Can not construct a file locator in InputFileCatalog::init";
+            ex.addContext("Calling edm::InputFileCatalog::init()");
+            throw ex;
+          }
         }
       }
     } else {