Fresh start, re-install
1. Backup any Apps, data or scripts that you have created and want to save (these are in C:\Lianja\Apps and C:\Lianja\data. Library scripts are in C:\Lianja\library)
2. Assuming you installed in the default location, files are installed here (Win64):
C:\Program Files (x86)\Lianja
So, delete these folders.
Should be fine to just install over the top as long as your existing installation is in the default C:\Lianja. If you installed on an alternative drive, unset or remove any environment variables you set up for the installer before running the new one. If you installed in an alternative directory I would deactivate, uninstall and start from clean.
Unpack your .lpk file from the Apps Workspace. Just click the ‘Install package’ button and it will open a file dialog to allow you to select your package.