Error while running "online_l1lr.conf"

[JerryLead]

$ ./local.sh 1 4 ../config/rcv1/online_l1lr.conf
I1208 16:39:02.350265 28809 postoffice.cc:67] Scheduler connected 1 servers and 4 workers
I1208 16:39:02.351523 28809 scheduler.cc:43] Found 13 training files
I1208 16:39:02.351568 28809 scheduler.cc:46] Assigned 13 files to 4 workers
F1208 16:39:02.511814 28877 ftrl_worker.cc:25] Check failed: ins.size() == 2 (0 vs. 2) 
*** Check failure stack trace: ***
    @     0x7f094e1ecbcd  google::LogMessage::Fail()
    @     0x7f094e1eeb48  google::LogMessage::SendToLog()
    @     0x7f094e1ec763  google::LogMessage::Flush()
    @     0x7f094e1ef47e  google::LogMessageFatal::~LogMessageFatal()
    @           0x487a6a  _ZNSt17_Function_handlerIFbPN2PS2LM10FTRLWorker9MinibatchEPmEZNS2_15computeGradientEvEUlS4_S5_E_E9_M_invokeERKSt9_Any_dataS4_S5_
    @           0x48a777  _ZNSt6thread5_ImplISt12_Bind_simpleIFZN2PS16ProducerConsumerINS2_2LM10FTRLWorker9MinibatchEE13startProducerERKSt8functionIFbPS6_PmEEEUlvE_vEEE6_M_runEv
    @     0x7f094d94fbf0  (unknown)
    @     0x7f094dbaa182  start_thread
    @     0x7f094d0b730d  clone
F1208 16:39:02.620822 28874 ftrl_worker.cc:25] Check failed: ins.size() == 2 (0 vs. 2) 
*** Check failure stack trace: ***
    @     0x7f7cdd7f4bcd  google::LogMessage::Fail()
    @     0x7f7cdd7f6b48  google::LogMessage::SendToLog()
    @     0x7f7cdd7f4763  google::LogMessage::Flush()
    @     0x7f7cdd7f747e  google::LogMessageFatal::~LogMessageFatal()
    @           0x487a6a  _ZNSt17_Function_handlerIFbPN2PS2LM10FTRLWorker9MinibatchEPmEZNS2_15computeGradientEvEUlS4_S5_E_E9_M_invokeERKSt9_Any_dataS4_S5_
    @           0x48a777  _ZNSt6thread5_ImplISt12_Bind_simpleIFZN2PS16ProducerConsumerINS2_2LM10FTRLWorker9MinibatchEE13startProducerERKSt8functionIFbPS6_PmEEEUlvE_vEEE6_M_runEv
    @     0x7f7cdcf57bf0  (unknown)
    @     0x7f7cdd1b2182  start_thread
    @     0x7f7cdc6bf30d  clone