mjhjmtu

I'm using manjaro KDE and I have this problem where I can't update system, get any file from pacman while the mirrors are online and I'm connected to internet.

$ pacman -Fs
warning: database file for 'core' does not exist
warning: database file for 'extra' does not exist
warning: database file for 'community' does not exist
warning: database file for 'multilib' does not exist
warning: database file for 'blackarch' does not exist
error: no targets specified (use -h for help)

$ sudo pacman -Syu 
:: Synchronizing package databases...
error: failed retrieving file 'core.db' from manjaro.barata.pt : The requested URL returned error: 404
error: failed retrieving file 'core.db' from manjaro.telecoms.bg : The requested URL returned error: 404
error: failed retrieving file 'core.db' from mirror.ventraip.net.au : The requested URL returned error: 404
error: failed retrieving file 'core.db' from ftp.halifax.rwth-aachen.de : The requested URL returned error: 404
error: failed retrieving file 'core.db' from repo.sadjad.ac.ir : The requested URL returned error: 404
error: failed to update core (unexpected error)
error: failed retrieving file 'extra.db' from manjaro.barata.pt : The requested URL returned error: 404
error: failed retrieving file 'extra.db' from manjaro.telecoms.bg : The requested URL returned error: 404
error: failed retrieving file 'extra.db' from mirror.ventraip.net.au : The requested URL returned error: 404
error: failed retrieving file 'extra.db' from ftp.halifax.rwth-aachen.de : The requested URL returned error: 404
error: failed retrieving file 'extra.db' from repo.sadjad.ac.ir : The requested URL returned error: 404
error: failed to update extra (unexpected error)
error: failed retrieving file 'community.db' from manjaro.barata.pt : The requested URL returned error: 404
error: failed retrieving file 'community.db' from manjaro.telecoms.bg : The requested URL returned error: 404
error: failed retrieving file 'community.db' from mirror.ventraip.net.au : The requested URL returned error: 404
error: failed retrieving file 'community.db' from ftp.halifax.rwth-aachen.de : The requested URL returned error: 404
error: failed retrieving file 'community.db' from repo.sadjad.ac.ir : The requested URL returned error: 404
error: failed to update community (unexpected error)
error: failed retrieving file 'multilib.db' from manjaro.barata.pt : The requested URL returned error: 404
error: failed retrieving file 'multilib.db' from manjaro.telecoms.bg : The requested URL returned error: 404
error: failed retrieving file 'multilib.db' from mirror.ventraip.net.au : The requested URL returned error: 404
error: failed retrieving file 'multilib.db' from ftp.halifax.rwth-aachen.de : The requested URL returned error: 404
error: failed retrieving file 'multilib.db' from repo.sadjad.ac.ir : The requested URL returned error: 404
error: failed to update multilib (unexpected error)
 blackarch is up to date
:: Starting full system upgrade...
resolving dependencies...
looking for conflicting packages...

Packages (156) ark-17.12.1-1 attica-qt5-5.42.0-1 baloo-5.42.0-1
 baloo-widgets-17.12.1-1 beef-1:2993.521e5c3e-1
 bluez-qt-5.42.0-1 breeze-icons-5.42.0-1 cantata-2.2.0-3
 dolphin-17.12.1-1 dolphin-plugins-17.12.1-1 ffmpeg-1:3.4.1-3
 ffmpegthumbs-17.12.1-1 filelight-17.12.1-1
 frameworkintegration-5.42.0-1 freetype2-2.9-1 glib2-2.54.3-2
 gst-plugins-bad-1.12.4-2 gst-plugins-ugly-1.12.4-3
 gtk2-2.24.32-1 gvfs-1.34.1+11+gad63dfb7-1
 gvfs-afc-1.34.1+11+gad63dfb7-1
 gvfs-gphoto2-1.34.1+11+gad63dfb7-1
 gvfs-mtp-1.34.1+11+gad63dfb7-1 gvfs-nfs-1.34.1+11+gad63dfb7-1
 gvfs-smb-1.34.1+11+gad63dfb7-1 gwenview-17.12.1-1 inxi-2.3.56-1
 k3b-1:17.12.1-1 kaccounts-integration-17.12.1-1
 kaccounts-providers-17.12.1-1 kactivities-5.42.0-1
 kactivities-stats-5.42.0-1 kamera-17.12.1-1 karchive-5.42.0-1
 kate-17.12.1-1 kauth-5.42.0-1 kbookmarks-5.42.0-1
 kcalc-17.12.1-1 kcmutils-5.42.0-1 kcodecs-5.42.0-1
 kcompletion-5.42.0-1 kconfig-5.42.0-1 kconfigwidgets-5.42.0-1
 kcoreaddons-5.42.0-1 kcrash-5.42.0-1 kdbusaddons-5.42.0-1
 kdeclarative-5.42.0-1 kdeconnect-1.2.1-1 kded-5.42.0-1
 kdegraphics-thumbnailers-17.12.1-1 kdelibs4support-5.42.0-1
 kdenetwork-filesharing-17.12.1-1 kdesu-5.42.0-1
 kdialog-17.12.1-1 kdnssd-5.42.0-1 kdoctools-5.42.0-1
 keditbookmarks-17.12.1-1 kemoticons-5.42.0-1
 kfilemetadata-5.42.0-1 kfind-17.12.1-1 kget-17.12.1-1
 kglobalaccel-5.42.0-1 kguiaddons-5.42.0-1 khelpcenter-17.12.1-1
 kholidays-17.12.1-1 khtml-5.42.0-1 ki18n-5.42.0-1
 kiconthemes-5.42.0-1 kidletime-5.42.0-1 kimageformats-5.42.0-1
 kinit-5.42.0-1 kio-5.42.0-1 kio-extras-17.12.1-1
 kirigami2-5.42.0-1 kitemmodels-5.42.0-1 kitemviews-5.42.0-1
 kjobwidgets-5.42.0-1 kjs-5.42.0-1 kjsembed-5.42.0-1
 knewstuff-5.42.0-1 knotifications-5.42.0-1
 knotifyconfig-5.42.0-1 konsole-17.12.1-1 kpackage-5.42.0-1
 kparts-5.42.0-1 kpeople-5.42.0-1 kpty-5.42.0-1
 krunner-5.42.0-1 kservice-5.42.0-1 ksystemlog-17.12.1-1
 ktexteditor-5.42.0-1 ktextwidgets-5.42.0-1 kuiserver-5.11.5-2
 kunitconversion-5.42.0-1 kwallet-5.42.0-1
 kwalletmanager-17.12.1-1 kwayland-5.42.0-1
 kwidgetsaddons-5.42.1-1 kwindowsystem-5.42.0-1 kxmlgui-5.42.0-1
 lib32-mesa-17.3.2-2 lib32-mesa-vdpau-17.3.2-2
 lib32-systemd-236.81-1 libcdio-2.0.0-1
 libcdio-paranoia-10.2+0.94+2-2 libkcddb-17.12.1-1
 libkdcraw-17.12.1-1 libkexiv2-17.12.1-1 libkipi-17.12.1-1
 libksane-17.12.1-1 libnm-1.10.3dev+38+g78ef57197-1
 libnm-glib-1.10.3dev+38+g78ef57197-1 libpagemaker-0.0.4-1
 libqalculate-2.2.1-1 librsvg-2:2.42.0-1 libseccomp-2.3.2-2
 libsoup-2.60.3-1 libsrtp-1:2.1.0-1 libsystemd-236.81-1
 libva-mesa-driver-17.3.2-2 libwebp-0.6.1-1
 libx264-2:152.20171224-1 libx264-all-2:152.20171224-1
 linux414-4.14.14-1 linux414-nvidia-1:384.111-3
 manjaro-release-17.1.2-1 mesa-17.3.2-2 mesa-vdpau-17.3.2-2
 mhwd-0.6.1-1 mhwd-db-0.6.1-1 modemmanager-qt-5.42.0-1
 mpd-0.20.15-2 networkmanager-1.10.3dev+38+g78ef57197-1
 networkmanager-qt-5.42.0-1 okular-17.12.1-1
 oxygen-icons-1:5.42.0-1 perl-xml-libxml-2.0132-1
 plasma-framework-5.42.0-1 plasma-workspace-5.11.5-2
 polkit-0.113+34+g29ba7af-1.1 potrace-1.15-1
 print-manager-17.12.1-1 prison-5.42.0-1
 qqc2-desktop-style-5.42.0-1 signon-kwallet-extension-17.12.1-1
 solid-5.42.0-1 sonnet-5.42.0-1 spectacle-17.12.1-1
 syntax-highlighting-5.42.0-1 systemd-236.81-1
 systemd-sysvcompat-236.81-1 threadweaver-5.42.0-1 tslib-1.15-1
 vcdimager-2.0.1-1 vlc-nightly-3.0.0v20180114-1 yakuake-3.0.4-2

Total Download Size: 297.51 MiB
Total Installed Size: 960.03 MiB
Net Upgrade Size: 6.49 MiB

:: Proceed with installation? [Y/n] 

Help would be appreciated.

This is almost always caused by the fact that your network is not configured or connected which could be caused by user error such as not connecting the cable or a missing driver for some wifi cards.