CDO

Hi Guys,
I have followed previous provided solutions but I could not resolve this issue for my case, I get the errors below. I will appreciate your help!
Faj

CDO version 1.7.2, Copyright (C) 2003-2016 Uwe Schulzweida
$ cdo sinfo CDR_tz.nc
File format : NetCDF4 ZIP
-1 : Institut Source Steptype Levels Num Points Num Dtype : Parameter ID
1 : unknown unknown instant 1 1 2070 1 F32z : -1
Grid coordinates :
1 : generic : points=2070 (46x45)
lon : 29.25 to 40.5 by 0.25
lat : -0.5 to -11.5 by -0.25
Vertical coordinates :
1 : surface : levels=1
Time coordinate : 12539 steps
RefTime = 1983-01-01 00:00:00 Units = days Calendar = standard
YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss
1983-01-01 00:00:00 1983-01-02 00:00:00 1983-01-03 00:00:00 1983-01-04 00:00:00

$ cdo sellonlatbox,37.55,39.15,-5.35,-3.75 CDR_tz.nc CDR_tzsub.nc
cdo sellonlatbox: Unsupported grid type: generic
cdo sellonlatbox (Abort): Unsupported grid type!

$ cdo sellonlatbox,37.55,39.15,-5.35,-3.75 -setgrid,CDR_tz.nc CDR_tz.nc CDR_tzsub.nc
cdo sellonlatbox: Started child process "setgrid,CDR_tz.nc CDR_tz.nc (pipe1.1)".
cdo sellonlatbox: Unsupported grid type: generic

$ cdo sellonlatbox,37.55,39.15,-5.35,-3.75 -setgrid,grid.txt CDR_tz.nc CDR_tzsub.nc
cdo sellonlatbox: Started child process "setgrid,grid.txt CDR_tz.nc (pipe1.1)".
cdo(2) setgrid (Abort): Open failed on grid.txt!