Loadiine have very errors in-game because it loads into another application (Mostly Mii Maker and Super Smash Bros).
To work properly you need to install the game in the System Memory or on a USB, here are the steps:
1 - Download the installable files, i do not recommend to use WUD files or .app's from any web, you need to download by you, using Windows applications like Wii U USB Helper (The best option, and very recommended):
https://gbatemp.net/threads/release-wii-u-usb-helper-a-small-eshop-for-windows.446565/ and put the URL with the first page in
THIS GOOGLE SEARCH, and these are other methods, but are not recommended having the USB Helper: (NUSGrabber)
https://wiidatabase.de/wii-u-downloads/pc-tools/nusgrabber/, (A tutorial in Spanish of NUSGrabber)
, (JNUSTool)
https://gbatemp.net/threads/jnustool-nusgrabber-and-cdecrypt-combined.413179/.
2 - A method to run homebrew, i think you have it to run Loadiine but just in case you can use (CBHC very recommended, and it autoboot)
https://gbatemp.net/threads/cbhc-v1-6-coldboot-haxchi-cfw.452615/, (Haxchi, if you dont want autoboot (It is understandable) its the best option)
https://gbatemp.net/threads/haxchi-v2-5u2-a-persistent-wiiu-hack.451071/ (Mocha)
https://gbatemp.net/threads/mocha-cfw-the-sweet-chocolate-to-your-latte.452940/ or (SigPatcher2sysmenu/HBL)
https://www.wiiubru.com/appstore/#/app/sigpatcher2sysmenu/
https://www.wiiubru.com/appstore/#/app/sigpatcher2HBL
3 - A tool to install games, you can use (Very recommended) WUP Installer GX2
https://www.wiiubru.com/appstore/#/app/wup_installer_gx2, if you have problems, use WUP Installer Y Mod (Is the same witout a GUI)
https://gbatemp.net/threads/wupinstaller-y-mod-with-multiple-install-folders.445907/
4 Do region free, to use games from another region. If you have CBHC with "sysmenu" option you dont need this, else do RegionHax (My option)
https://gbatemp.net/threads/regionhax-how-to-get-regionfree-on-wiiu.448468/ and here a tutorial in Spanish
4 - Enjoy it! And use these methods, loadiine in few cases is unstable or slow, remember it
, and thanks because of the name