Cannot import the page as an asset

I think it's the same problem someone was having here. See if this helps you:

https://cgcookie.mavenseed.com/community/14008-install-application-template-did-not-work-for-me

Hey Nickolas! It may be defaulting to "Current File" - first, switch the Asset Browser to "User Library". Assuming you put your template in a defined Catalogue, and the .blend File is in a folder on your system where Blender is looking for Library Assets,it should show up

In your Blender Preferences, here is where User Library can be assigned

You can leave Blender's defaults, and add your own custom folders  - this way, you might organize specific .blend libraries however you wish, and just enable them for when you need them.

Make sure you pull out any collections/assets assigned into a catalogue before saving. They will first show up in the "unassigned" default catalogue.