TypeError : '>' not supported between instances of 'int' and 'str'

The command I entered is
MG5_aMC>generate g g > n2 vv QED<=3 [QCD]
output GGF_Nv_LO; launch;

While the result is
INFO: initialize a new directory: GGF_Nv_LO
INFO: remove old information in GGF_Nv_LO
INFO: Organizing processes into subprocess groups
INFO: Generating Helas calls for process: g g > n2 vm QCD<=99 QED<=3 [ noborn = QCD ]
INFO: Processing color information for loop process: g g > n2 vm QCD<=99 QED<=3 [ noborn = QCD ]
INFO: Creating color matrix loop process: g g > n2 vm QCD<=99 QED<=3 [ noborn = QCD ]
INFO: Generating Helas calls for process: g g > n2 vm~ QCD<=99 QED<=3 [ noborn = QCD ]
INFO: Processing color information for loop process: g g > n2 vm~ QCD<=99 QED<=3 [ noborn = QCD ]
INFO: Creating color matrix loop process: g g > n2 vm~ QCD<=99 QED<=3 [ noborn = QCD ]
INFO: Creating files in directory /root/MG5_aMC_v3_3_1/GGF_Nv_LO/SubProcesses/PV0_0_1_gg_n2vm
INFO: Computing diagram color coefficients
INFO: Drawing loop Feynman diagrams for Process: g g > n2 vm QCD<=99 QED<=3 [ noborn = QCD ]
INFO: Creating files in directory /root/MG5_aMC_v3_3_1/GGF_Nv_LO/SubProcesses/PV0_0_2_gg_n2vmx
INFO: Computing diagram color coefficients
INFO: Drawing loop Feynman diagrams for Process: g g > n2 vm~ QCD<=99 QED<=3 [ noborn = QCD ]
INFO: Creating files in directory P0_gg_n2vl
INFO: Generating Feynman diagrams for Process: g g > n2 vm QCD<=99 QED<=3 [ noborn = QCD ]
INFO: Generating Feynman diagrams for Process: g g > n2 vm~ QCD<=99 QED<=3 [ noborn = QCD ]
Command "output GGF_Nv_LO; launch;" interrupted in sub-command:
"output GGF_Nv_LO" with error:
TypeError : '>' not supported between instances of 'int' and 'str'
Please report this bug on https://bugs.launchpad.net/mg5amcnlo
More information is found in 'MG5_debug'.
Please attach this file to your report.

Do you have any good suggestions？
Thanks！