I have another updated question now, sorry!!
I applied resfile flag in backrub, and it ran OK.
But why did it go to deadlock in floppytail? I really used the same structure and resfile…
It was displayed
can not find a residue type that matches the residue CA at position xxx
ERROR: switch_to_residue_type_set fails
ERROR:: Exit from: src/core/chemical/util.cc line: 645
Thanks very much for your patience and help.