IDA Pro7.5 && Python3 not working

[Double-q1015]

I tried to modify the code in Gopclntab.py

before
def rename(beg, ptr, make_funcs = True):
....
name = idc.get_strlit_contents(base + name_offset)
name = Utils.relaxName(name)
Utils.rename(func_addr, name)

after
def rename(beg, ptr, make_funcs = True):
.....
name = idc.get_strlit_contents(base + name_offset)
name = name.decode("utf-8")
name = Utils.relaxName(name)
Utils.rename(func_addr, name)

[k1nm0]

same error