Errors plotting with TGraph2D and setting axis titles

ROOT
15

For BOTH your “ROOT installations”, try (inspect absolute paths of all libraries reported by “ldd”):
root-config --bindir
ldd root-config --bindir/root.exe
root-config --libdir
ldd root-config --libdir/libTree.so
root-config --etcdir
BTW. You MUST have different “etcdir” for different “ROOT installations”.