Fixing the Unity3D 5.3 startup error on Linux

If you experience this error with the newest Unity3D Build on Linux, just do this one simple step:

=> Image

• Create the folder ~/.local/share/unity3d and you are good to go!

Now have fun with Unity!

In more detail, the "main" error message in ~/.config/unity3d/Editor.log is

CopyPackageFile failed, unable to copy /opt/Unity/Editor/Data/Resources/Packages/unity-editor-home-0.0.7.tgz to /home/luca/.local/share/unity3d/Packages/unity-editor-home-0.0.7.tgz

CopyPackageFile failed, unable to copy /opt/Unity/Editor/Data/Resources/Packages/unityeditor-cloud-hub-0.0.1.tgz to /home/luca/.local/share/unity3d/Packages/unityeditor-cloud-hub-0.0.1.tgz