The package is not built with the recommended structure

[Simferoce]

The package should follow the recommended structure. The "install from tarball" functionality does not work without modifying the package.

https://docs.unity3d.com/6000.1/Documentation/Manual/CustomPackages.html

[yasirkula]

The trick is to have a root package folder in the tarball: https://discussions.unity.com/t/package-manager-does-not-import-from-tarball/900105/2

UnityIngameDebugConsole.tar.gz