I have installed the pack to 5.5 but the assets do not show up in the Content browser. The directories show empty. I installed from both fab.com and also using the Fab plugin. The .uasset files are there. I also tried this with multiple projects with the same result. There must be something wrong with the distributed files. I have not tried installing it to a 5.6 project (yet). You listed 5.5 as supported and the installer didn’t give any warnings.