Check that PropertyVector exists before fetching.

Applications/DataExplorer/DataView/ElementTreeModel.cpp

...ations/DataExplorer/DataView/MeshElementRemovalDialog.cpp

Applications/FileIO/SHPInterface.cpp

Applications/FileIO/TetGenInterface.cpp

...cations/Utils/FileConverter/generateMatPropsFromMatID.cpp

...tions/Utils/MeshEdit/ResetPropertiesInPolygonalRegion.cpp

Applications/Utils/MeshEdit/queryMesh.cpp

...tils/ModelPreparation/ComputeNodeAreasFromSurfaceMesh.cpp

Applications/Utils/ModelPreparation/createNeumannBc.cpp

MeshGeoToolsLib/AppendLinesAlongPolyline.cpp

MeshLib/ElementStatus.cpp

MeshLib/IO/Legacy/MeshIO.cpp

MeshLib/Mesh.cpp

MeshLib/MeshEditing/AddLayerToMesh.cpp

MeshLib/MeshEditing/ConvertToLinearMesh.cpp

MeshLib/MeshEditing/ElementValueModification.cpp

MeshLib/MeshEditing/Mesh2MeshPropertyInterpolation.cpp

MeshLib/MeshEditing/MeshRevision.cpp

MeshLib/MeshInformation.h

MeshLib/MeshSearch/ElementSearch.h