I just updated from jessie to ascii and it gives me 2 errors:
How could I solve these errors?

First:
[GNUPG:] ERROR add_keyblock_resource 33554433
[GNUPG:] NEWSIG
[GNUPG:] ERROR keydb_search 33554445
[GNUPG:] ERRSIG 94532124541922FB 1 8 00 1511158266 9
[GNUPG:] NO_PUBKEY 94532124541922FB
gpgv: unknown type of key resource 'trustedkeys.kbx'
gpgv: keyblock resource '/root/.gnupg/trustedkeys.kbx': General error
gpgv: Firmado el lun 20 nov 2017 01:11:06 CST
gpgv:                usando RSA clave 94532124541922FB
gpgv: Imposible comprobar la firma: No public key
.temp/.tmp/dists/ascii/Release.gpg signature does not verify.
[GNUPG:] ERROR add_keyblock_resource 33554433
[GNUPG:] NEWSIG
[GNUPG:] ERROR keydb_search 33554445
[GNUPG:] ERRSIG 94532124541922FB 1 8 01 1511158263 9
[GNUPG:] NO_PUBKEY 94532124541922FB

Second: when I start the system I get the following message:
error: ninguna tabla de simbolos.
Cargando Linux 4.9.0-4-686-pae...
Cargando imagen de memoria inicial...

Presione cualquier tecla para continuar...

translated

error: no table of symbols.
Loading Linux 4.9.0-4-686-pae ...
Loading initial memory image ...

Press any key to continue...

the grub.cfg file:

# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
set have_grubenv=true
load_env
fi
if [ "${next_entry}" ] ; then
set default="${next_entry}"
set next_entry=
save_env next_entry
set boot_once=true
else
set default="0"
fi

if [ x"${feature_menuentry_id}" = xy ]; then
menuentry_id_option="--id"
else
menuentry_id_option=""
fi

export menuentry_id_option

if [ "${prev_saved_entry}" ]; then
set saved_entry="${prev_saved_entry}"
save_env saved_entry
set prev_saved_entry=
save_env prev_saved_entry
set boot_once=true
fi

function savedefault {
  if [ -z "${boot_once}" ]; then
    saved_entry="${chosen}"
    save_env saved_entry
  fi
}
function load_video {
  if [ x$feature_all_video_module = xy ]; then
    insmod all_video
  else
    insmod efi_gop
    insmod efi_uga
    insmod ieee1275_fb
    insmod vbe
    insmod vga
    insmod video_bochs
    insmod video_cirrus
  fi
}

if [ x$feature_default_font_path = xy ] ; then
   font=unicode
else
insmod part_msdos
insmod ext2
set root='hd1,msdos1'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 --hint='hd1,msdos1'  a7624410-03a1-4528-9f5a-8d0bc92015cd
else
  search --no-floppy --fs-uuid --set=root a7624410-03a1-4528-9f5a-8d0bc92015cd
fi
    font="/usr/share/grub/unicode.pf2"
fi

if loadfont $font ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  set locale_dir=$prefix/locale
  set lang=es_ES
  insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ] ; then
  set timeout=30
else
  if [ x$feature_timeout_style = xy ] ; then
    set timeout_style=menu
    set timeout=5
  # Fallback normal timeout code in case the timeout_style feature is
  # unavailable.
  else
    set timeout=5
  fi
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=cyan/blue
set menu_color_highlight=white/blue
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
function gfxmode {
 set gfxpayload="${1}"
}
set linux_gfx_mode=
export linux_gfx_mode
menuentry 'Devuan GNU/Linux' --class devuan --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-a7624410-03a1-4528-9f5a-8d0bc92015cd' {
 load_video
 insmod gzio
 if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
 insmod part_msdos
 insmod ext2
 set root='hd1,msdos1'
 if [ x$feature_platform_search_hint = xy ]; then
   search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 --hint='hd1,msdos1'  a7624410-03a1-4528-9f5a-8d0bc92015cd
 else
   search --no-floppy --fs-uuid --set=root a7624410-03a1-4528-9f5a-8d0bc92015cd
 fi
 echo 'Cargando Linux 4.9.0-4-686-pae...'
 linux /boot/vmlinuz-4.9.0-4-686-pae root=UUID=a7624410-03a1-4528-9f5a-8d0bc92015cd ro  quiet
 echo 'Cargando imagen de memoria inicial...'
 initrd /boot/initrd.img-4.9.0-4-686-pae
}
submenu 'Opciones avanzadas para Devuan GNU/Linux' $menuentry_id_option 'gnulinux-advanced-a7624410-03a1-4528-9f5a-8d0bc92015cd' {
 menuentry 'Devuan GNU/Linux, con Linux 4.9.0-4-686-pae' --class devuan --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.9.0-4-686-pae-advanced-a7624410-03a1-4528-9f5a-8d0bc92015cd' {
  load_video
  insmod gzio
  if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
  insmod part_msdos
  insmod ext2
  set root='hd1,msdos1'
  if [ x$feature_platform_search_hint = xy ]; then
    search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 --hint='hd1,msdos1'  a7624410-03a1-4528-9f5a-8d0bc92015cd
  else
    search --no-floppy --fs-uuid --set=root a7624410-03a1-4528-9f5a-8d0bc92015cd
  fi
  echo 'Cargando Linux 4.9.0-4-686-pae...'
  linux /boot/vmlinuz-4.9.0-4-686-pae root=UUID=a7624410-03a1-4528-9f5a-8d0bc92015cd ro  quiet
  echo 'Cargando imagen de memoria inicial...'
  initrd /boot/initrd.img-4.9.0-4-686-pae
 }
 menuentry 'Devuan GNU/Linux, with Linux 4.9.0-4-686-pae (sysvinit)' --class devuan --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.9.0-4-686-pae-init-sysvinit-a7624410-03a1-4528-9f5a-8d0bc92015cd' {
  load_video
  insmod gzio
  if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
  insmod part_msdos
  insmod ext2
  set root='hd1,msdos1'
  if [ x$feature_platform_search_hint = xy ]; then
    search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 --hint='hd1,msdos1'  a7624410-03a1-4528-9f5a-8d0bc92015cd
  else
    search --no-floppy --fs-uuid --set=root a7624410-03a1-4528-9f5a-8d0bc92015cd
  fi
  echo 'Cargando Linux 4.9.0-4-686-pae...'
  linux /boot/vmlinuz-4.9.0-4-686-pae root=UUID=a7624410-03a1-4528-9f5a-8d0bc92015cd ro  quiet init=/lib/sysvinit/init
  echo 'Cargando imagen de memoria inicial...'
  initrd /boot/initrd.img-4.9.0-4-686-pae
 }
 menuentry 'Devuan GNU/Linux, with Linux 4.9.0-4-686-pae (recovery mode)' --class devuan --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.9.0-4-686-pae-recovery-a7624410-03a1-4528-9f5a-8d0bc92015cd' {
  load_video
  insmod gzio
  if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
  insmod part_msdos
  insmod ext2
  set root='hd1,msdos1'
  if [ x$feature_platform_search_hint = xy ]; then
    search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 --hint='hd1,msdos1'  a7624410-03a1-4528-9f5a-8d0bc92015cd
  else
    search --no-floppy --fs-uuid --set=root a7624410-03a1-4528-9f5a-8d0bc92015cd
  fi
  echo 'Cargando Linux 4.9.0-4-686-pae...'
  linux /boot/vmlinuz-4.9.0-4-686-pae root=UUID=a7624410-03a1-4528-9f5a-8d0bc92015cd ro single 
  echo 'Cargando imagen de memoria inicial...'
  initrd /boot/initrd.img-4.9.0-4-686-pae
 }
}

### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###

### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/30_uefi-firmware ###
### END /etc/grub.d/30_uefi-firmware ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f ${config_directory}/custom.cfg ]; then
source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f $prefix/custom.cfg ]; then
source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###


Best Regards
--
Ismael