error while building compiler

g++ -fPIC -std=c++11 -Wall -O3 -g -I./JDI/src -I../shared -I../shared/libpng-util -I../shared/protos/codegen  -I. -MMD -MP -c -o .eobjs/./compiler/jdi_utility.o compiler/jdi_utility.cpp
g++ -fPIC -std=c++11 -Wall -O3 -g -I./JDI/src -I../shared -I../shared/libpng-util -I../shared/protos/codegen  -I. -MMD -MP -c -o .eobjs/./compiler/compile_common.o compiler/compile_common.cpp
g++ -fPIC -std=c++11 -Wall -O3 -g -I./JDI/src -I../shared -I../shared/libpng-util -I../shared/protos/codegen  -I. -MMD -MP -c -o .eobjs/./compiler/compile.o compiler/compile.cpp
compiler/compile.cpp: In member function ‘virtual int lang_CPP::compile(const GameData&, const char*, int)’:
compiler/compile.cpp:440:56: error: no match for ‘operator[]’ (operand types are ‘const google::protobuf::RepeatedPtrField<buffers::resources::Timeline_Moment>’ and ‘int’)
         wto << "  curr[" << game.timelines[i].moments()[j].step()
                                                        ^
g++ -fPIC -std=c++11 -Wall -O3 -g -I./JDI/src -I../shared -I../shared/libpng-util -I../shared/protos/codegen  -I. -MMD -MP -c -o .eobjs/./filesystem/file_find.o filesystem/file_find.cpp
g++ -fPIC -std=c++11 -Wall -O3 -g -I./JDI/src -I../shared -I../shared/libpng-util -I../shared/protos/codegen  -I. -MMD -MP -c -o .eobjs/./frontend.o frontend.cpp
g++ -fPIC -std=c++11 -Wall -O3 -g -I./JDI/src -I../shared -I../shared/libpng-util -I../shared/protos/codegen  -I. -MMD -MP -c -o .eobjs/./main.o main.cpp
g++ -fPIC -std=c++11 -Wall -O3 -g -I./JDI/src -I../shared -I../shared/libpng-util -I../shared/protos/codegen  -I. -MMD -MP -c -o .eobjs/./settings.o settings.cpp
g++ -fPIC -std=c++11 -Wall -O3 -g -I./JDI/src -I../shared -I../shared/libpng-util -I../shared/protos/codegen  -I. -MMD -MP -c -o .eobjs/./makedir.o makedir.cpp
g++ -fPIC -std=c++11 -Wall -O3 -g -I./JDI/src -I../shared -I../shared/libpng-util -I../shared/protos/codegen  -I. -MMD -MP -c -o .eobjs/./compiler/compile.o compiler/compile.cpp
compiler/compile.cpp: In member function ‘virtual int lang_CPP::compile(const GameData&, const char*, int)’:
compiler/compile.cpp:440:56: error: no match for ‘operator[]’ (operand types are ‘const google::protobuf::RepeatedPtrField<buffers::resources::Timeline_Moment>’ and ‘int’)
         wto << "  curr[" << game.timelines[i].moments()[j].step()
                                                        ^