[WSTAT error] encountering 'fractional occupation degenerate orbitals' when executing wstat.x

[yliu1240]

Hi, all!
I'm running wstat.x on a structure of bulk Li metal with 1 interstitial but encountering the following error:
"""

 Sternheimer eq. solver... with lite-solver

---

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Error in routine dfpt (1):
fractional occupation degenerate orbitals
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
"""

Here's my setting for wstat_control:
"""
wstat_control:
wstat_calculation: S
n_pdep_eigen: 200
trev_pdep: 0.00001
"""

And my setting for pw.x before performing wstat.x:
"""
&CONTROL
calculation = 'scf'
restart_mode = 'from_scratch'
wf_collect = .true.
outdir = './'
prefix = 'i011'
etot_conv_thr = 1e-06
pseudo_dir = './'
/
&SYSTEM
ecutwfc = 60
occupations = 'smearing'
degauss = 0.01
smearing = 'gaussian'
nspin = 1
ntyp = 1
nat = 129
ibrav = 0
/
&ELECTRONS
electron_maxstep = 200
conv_thr = 1e-07
/

ATOMIC_SPECIES
Li 6.94 Li_ONCV_PBE-1.2.upf

K_POINTS gamma

CELL_PARAMETERS angstrom
......
"""

The Li interstitial system has 233 bands and 387 electrons as shown in pw.x calculations.
I guess it's some problem in my setting for the calculation of wstat.x. Or, is it because of the gamma k-point?

Is there any more information I should provide to understand the problem?

Thanks in advance and have a nice day!

Best,