Download Unity 2021 2021.1.22f1

Improvements
- Graphics: Reduced main thread hitching caused by Shader loading
- iOS: Reduce memory usage for small uploads in UnityWebRequest. (1355235)
- Particles: Optimize Mesh data stripping vertex channels that are used by particle systems when the mesh is included in assetbundles. (1313420)

Changes
- Graphics: Updated the embedded (external) TinyExr library to v1.0 (1345230)
- Package Manager: The Git LFS cache enabled by setting the UPM_ENABLE_GIT_LFS_CACHE environment variable is now always located under the global cache root, even when the cache root location is customized.
- XR: Updated XR Interaction Toolkit to 1.0.0-pre.5. Please refer to the package changelog online here: https://docs.unity3d.com/Packages/com.unity.xr.interaction.toolkit@1.0/changelog/CHANGELOG.html

Fixes
- 2D: Fixed a potential crash caused by a race condition when loading SpriteRenderer from multiple threads. (1351843)
- Audio: Fixed a crash when passing a null argument to AudioMixer.FindSnapshot. (1341752)
- Graphics: Fixed an incorrect shader code generation when using half precision SV_POSITION. (1323558)
- Graphics: Fixed performance spikes in OSX while using an external monitor. Metal editor on OSX now uses CVDisplayLink to time frame presents. (1327408)
- Linux: Fixed an issue where the Assets menu was disabled after using the right-click context menu, or items in the context menu were unexpectedly disabled. (1346205)
- Package Manager: Fixed an issue where packages using Git LFS on Apple Silicon hardware would fail if Git LFS was installed through Homebrew and the Git LFS executable location was not added to the PATH environment variable. (1353769)
- Particles: Automatically mark textures as readable, if used by the Particle System Shape module. (1344356)
- Prefabs: Fixed a crash when GameObjects or Components are applied to Prefab while the Asset Pipeline was paused. (1324978)
- Profiler: Fixed an issue where the CPU Usage Profiler Chart did not show Vsync as the category when the editor was waiting in WaitForTargetFPS->TimeUpdate.WaitForLastPresentationAndUpdateTime for PS4, PS5, D3D11 and D3D12. (1335370)
- Shaders: Fixed an issue where Enabling "Optimize mesh data" in player settings made the build process significantly slower. (1349093)
- uGUI: Fixed an issue when multiple materials with multiple textures are assigned to a single UI Element did not rendered correctly. (1341814)
- Universal Windows Platform: Fixed a race-condition issue when using TouchScreenKeyboard's "text" or "selection" properties immediately after calling Open. (1345877)
- Universal Windows Platform: Fixed an issue where TouchScreenKeyboard on HoloLens2 closed a few seconds after focusing a TextMeshPro input field. (1360514)
- XR: Fixed an issue for late latching pre drawcall performance regression and world space UI and terrain always drawn at origin. (1337356, 1337972)
- XR: Fixed an issue with camera depth normals pass in XR. (1284715)