Install application in root path

Support
1

I am trying to install Mattermost from:

On the README it states that it can only be installed in the root path. But when I try to do so, I got an error like:

Warning: Unable to install the app in this location

There is no other app set as ‘default’ or installed into the root path.

2

Maybe you can’t install on root path if you have apps install on subpath. It is logic, cause your subpath apps could create conflict with the root apps.

Exemple:
The app on / need a directory called /files/ but your subpath apps is already installed on /files/…