Unity 5.0.0f4 -

The Asset Store underwent a massive API change in Unity 5. Many popular assets (Shader Forge, PlayMaker, NGUI) broke in 5.0.0f1/2/3. By f4, most major asset authors had released patches specifically targeting this version.

Yet, in the pantheon of Unity versions, f4 deserves respect. It was the foundation that allowed developers to trust Physically Based Rendering, to adopt real-time GI, and to finally move on from the hellish plugin-installation workflows of Unity 4. unity 5.0.0f4

Released in the spring of 2015, Unity 5.0.0f4 was not the initial launch of Unity 5 (that honor belongs to f1). Instead, it represents the fourth patch release of the groundbreaking Unity 5.0 cycle. For many studios and indie developers, this became the "golden build"—the stable foundation upon which hundreds of commercial projects were built. The Asset Store underwent a massive API change in Unity 5