Error in <TChain::SetBranchAddress>: Unable to determine typ


An error has suddenly started to appear at the beginning of the output from my code:

Error in TChain::SetBranchAddress: Unable to determine the type given for the address for “mu_pt”. The class expected (vector) refers to an stl collection and do not have a compiled CollectionProxy. Please generate the dictionary for this class (vector)

This doesn’t seem to change the results, but I would like to play it safe and fix this. My main program contains the following:

TChain* tree = new TChain("data","data");
std::vector<float>* vmu_pt= 0;

and the Makefile looks like:

CXX        = /usr/bin/g++
#Enable warnings and debugging info
CXXFLAGS   = -Wall -g
INCS      = `root-config --cflags` -I.
LIBS      = `root-config --libs` -lRooFit -lRooFitCore -lRooStats

WAnalysisHip : WAnalysisHip.o WAnalysisTool.o FitResult.o
        $(CXX) $(CXXFLAGS) -o $@ $< WAnalysisTool.o FitResult.o $(INCS) $(LIBS)

WAnalysisHip.o :
        $(CXX) $(CXXFLAGS) -c $< $(INCS) $(LIBS)

FitResult.o :
        $(CXX) $(CXXFLAGS) -c $< $(INCS) $(LIBS)

WAnalysisTool.o : WAnalysisTool.h
        $(CXX) $(CXXFLAGS) -c $< $(INCS) $(LIBS)

clean : 
        rm -f WAnalysisHip *.o

I tried adding to the Makefile

Dict.o : Dict.cxx
        $(CC) $(CCFLAGS) -c $< $(INCS) $(LIBS)

Dict.cxx :
        rootcint -f $@ -c $<+

But the error still appears. Any ideas?

Adding to my int main() scope

gROOT->ProcessLine("#include <vector>");

removes the errors.