Pythia error while merging NLO event

Dear Mg5 Team;

Hope everyone is safe and healthy. I'm having a problem with merging an NLO process. I'm using DMsimp model and trying to reproduce the past studies by generating

generate p p > xd xd~ j / y0 [QCD]
add process p p > xd xd~ j j / y0 [QCD]

using a restrict card to have either vector or axial vector mediator etc. I'm using FxFx merging with pythia8 where my ptj in the run card is 20 GeV and ickkw = 3 and in shower card im only changing qcut to 30 and njet to 2. I'm also modifying cuts.f to set leading jet pt > 150 GeV and MET > 250 GeV. MG5 generates the born level events without any issue but I get the attached error for Pythia. Note that I only saw this issue with this sample, I can generate this very event with a single jet without any issue in Pythia. Would be appreciated if you can help me to solve this problem.

Thanks a lot and stay safe
Best regards
Jack

----------------

MG5 Version
version = 2.6.5
date = 2018-02-03

--------mcatnlo.log:

/mt/batch/jaraz/MG5_aMC_v2_6_5/HEPTools/pythia8/lib/libpythia8.a(Streams.o): In function `Pythia8::gzstreambuf::open(char const*, int)':
Streams.cc:(.text+0xfc): undefined reference to `gzopen'
/mt/batch/jaraz/MG5_aMC_v2_6_5/HEPTools/pythia8/lib/libpythia8.a(Streams.o): In function `Pythia8::gzstreambuf::close()':
Streams.cc:(.text+0x17f): undefined reference to `gzclose'
/mt/batch/jaraz/MG5_aMC_v2_6_5/HEPTools/pythia8/lib/libpythia8.a(Streams.o): In function `Pythia8Pythia8 compilation did not succeed, exiting
t+0x2be): undefined reference to `gzread'
/mt/batch/jaraz/MG5_aMC_v2_6_5/HEPTools/pythia8/lib/libpythia8.a(Streams.o): In function `Pythia8::gzstreambuf::flush_buffer()':
Streams.cc:(.text+0x382): undefined reference to `gzwrite'
/mt/batch/jaraz/MG5_aMC_v2_6_5/HEPTools/pythia8/lib/libpythia8.a(PartonDistributions.o): In function `Pythia8::LHAPDF::LHAPDF(int, std::__cxx11::basic_string<char, std::char_traits\
<char>, std::allocator<char> >, Pythia8::Info*)':
PartonDistributions.cc:(.text+0x1064b): undefined reference to `dlopen'
PartonDistributions.cc:(.text+0x10661): undefined reference to `dlerror'
PartonDistributions.cc:(.text+0x10809): undefined reference to `dlerror'
/mt/batch/jaraz/MG5_aMC_v2_6_5/HEPTools/pythia8/lib/libpythia8.a(PartonDistributions.o): In function `Pythia8::LHAPDF::~LHAPDF()':
PartonDistributions.cc:(.text+0x10d26): undefined reference to `dlclose'
PartonDistributions.cc:(.text+0x10d2b): undefined reference to `dlerror'
/mt/batch/jaraz/MG5_aMC_v2_6_5/HEPTools/pythia8/lib/libpythia8.a(PartonDistributions.o): In function `Pythia8::LHAPDF::symbol(std::__cxx11::basic_string<char, std::char_traits<char\
>, std::allocator<char> >)':
PartonDistributions.cc:(.text+0x10e87): undefined reference to `dlsym'
PartonDistributions.cc:(.text+0x10e90): undefined reference to `dlerror'
PartonDistributions.cc:(.text+0x10f1f): undefined reference to `dlerror'
collect2: error: ld returned 1 exit status
make: *** [Pythia82] Error 1