failed to load external entity "./Materials.xml"

[Shaghayegh1996PhD]

please help me for this error.(when I run molecular-therapy-I131 example:)

[Core-0] Starting macro main.mac
I/O warning : failed to load external entity "./Materials.xml"
I/O warning: Discard the previous warning if your simulation doesn't transport OPTICAL PHOTONS.
Otherwise, please copy the ./Materials.xml file from the gate-source directory in the directory where you run your main macro.
[Physic-0] The following Geant4's physic-list is enabled :emstandard_opt3
[Core-0] Initialization of geometry

WARNING ### setSkipEqualMaterials at false !! The Geant4 method is not safe since the release 9.5 - Need to be fixed

WARNING ### setSkipEqualMaterials at false !! The Geant4 method is not safe since the release 9.5 - Need to be fixed

min max 0 18496 material: Air, visible false, rgba(0,0,0)
min max 18497 27749 material: AirBodyInterface, visible true, rgba(0.8,0,0)
I/O warning : failed to load external entity "./Materials.xml"
I/O warning: Discard the previous warning if your simulation doesn't transport OPTICAL PHOTONS.
Otherwise, please copy the ./Materials.xml file from the gate-source directory in the directory where you run your main macro.
min max 27750 37409 material: SoftTissue, visible true, rgba(0,0.8,0)
I/O warning : failed to load external entity "./Materials.xml"
I/O warning: Discard the previous warning if your simulation doesn't transport OPTICAL PHOTONS.
Otherwise, please copy the ./Materials.xml file from the gate-source directory in the directory where you run your main macro.
min max 37410 65535 material: Bones, visible true, rgba(0,0,0.8)
I/O warning : failed to load external entity "./Materials.xml"
I/O warning: Discard the previous warning if your simulation doesn't transport OPTICAL PHOTONS.
Otherwise, please copy the ./Materials.xml file from the gate-source directory in the directory where you run your main macro.
[Core-0] Initialization of physics
[Core-0] Initialization of actors
GateSourceVoxelInterfileReader.cc (l.25): GateSourceVoxelInterfileReader is obsolete, use GateSourceVoxelImageReader instead!