The "meta.xml" file for save-installer is broken. It has unescaped < and > characters in it.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<app version="1">
<name>Savegame Installer</name>
<coder>Waninkoko</coder>
<version>2</version>
<short_description>Installs dumped saves from your SD card</short_description>
<long_description>Copy the savegame you want to install to the SD card (directory "wiisaves/<game id>", just keep the directory structure created by the "Savegame Extractor").

Run this application.

Insert the game DVD and press RESET or A button (Wiimote not supported).</long_description>
</app>
Simplify and change it to this, and it should work. It did for me.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<app version="1">
<name>Savegame Installer</name>
<coder>Waninkoko</coder>
<version>2</version>
<short_description>Installs dumped saves from your SD card</short_description>
<long_description>Run this application.

Insert the game DVD and press RESET or A button (Wiimote not supported).</long_description>
</app>
Z.