Fix errors when loading an incompatible dataset.

include/engine/datafacade/contiguous_internalmem_datafacade.hpp

@@ -194,7 +194,7 @@ class ContiguousInternalMemoryDataFacadeBase : public BaseDataFacade
     extractor::ProfileProperties *m_profile_properties;
     extractor::Datasources *m_datasources;
 
-    unsigned m_check_sum;
+    std::uint32_t m_check_sum;
     util::vector_view<util::Coordinate> m_coordinate_list;
     extractor::PackedOSMIDsView m_osmnodeid_list;
     util::vector_view<std::uint32_t> m_lane_description_offsets;
@@ -242,7 +242,7 @@ class ContiguousInternalMemoryDataFacadeBase : public BaseDataFacade
 
     void InitializeChecksumPointer(const storage::DataLayout &data_layout, char *memory_block)
     {
-        m_check_sum = *data_layout.GetBlockPtr<unsigned>(memory_block, "/ch/checksum");
+        m_check_sum = *data_layout.GetBlockPtr<std::uint32_t>(memory_block, "/common/connectivity_checksum");
         util::Log() << "set checksum: " << m_check_sum;
     }
 
@@ -779,7 +779,7 @@ class ContiguousInternalMemoryDataFacadeBase : public BaseDataFacade
             input_coordinate, bearing, bearing_range, approach);
     }
 
-    unsigned GetCheckSum() const override final { return m_check_sum; }
+    std::uint32_t GetCheckSum() const override final { return m_check_sum; }
 
     GeometryID GetGeometryIndex(const NodeID id) const override final
     {

include/engine/datafacade/datafacade_base.hpp

@@ -53,7 +53,7 @@ class BaseDataFacade
     BaseDataFacade() {}
     virtual ~BaseDataFacade() {}
 
-    virtual unsigned GetCheckSum() const = 0;
+    virtual std::uint32_t GetCheckSum() const = 0;
 
     // node and edge information access
     virtual util::Coordinate GetCoordinateOfNode(const NodeID id) const = 0;

include/engine/datafacade_factory.hpp

@@ -57,6 +57,13 @@ template <template <typename A> class FacadeT, typename AlgorithmT> class DataFa
         layout.List(exclude_path, std::back_inserter(exclude_prefixes));
         facades.resize(exclude_prefixes.size());
 
+        if (facades.empty())
+        {
+            throw util::exception(std::string("Could not find any metrics for ") +
+                                  routing_algorithms::name<AlgorithmT>() +
+                                  " in the data. Did you load the right dataset?");
+        }
+
         for (const auto &exclude_prefix : exclude_prefixes)
         {
             auto index_begin = exclude_prefix.find_last_of("/");