Intellisense breaks in VSCode

I've never had a problem with Intellisense in VSCode before, but I keep getting errors when trying to use any scripts that comes within the Unity Test Framework. These errors only appear in the IDE and prevent my Intellisense from working, but the scripts compile fine in Unity.

I'm using the C# extension from Microsoft (powered by OmniSharp) and every other script in my project works fine.

The type or namespace name 'UnityTestAttribute' could not be found (are you missing a using directive or an assembly reference?) [Opsive.UltimateCharacterController, Assembly-CSharp, InControl, UIEffect, Assembly-CSharp-firstpass, AstarPathfindingProject, DissonanceVoip, PhotonBolt, PhotonRealtime, Opsive.UltimateCharacterController.Demo, InControl.Examples, Opsive.Shared, UIEffect_Demo, PhotonWebSocket]

The type or namespace name 'NUnit' could not be found (are you missing a using directive or an assembly reference?) [Opsive.UltimateCharacterController, Assembly-CSharp, InControl, InControl, InControl, InControl, InControl, InControl, InControl, InControl, InControl, InControl, InControl, InControl, UIEffect, UIEffect, UIEffect, UIEffect, UIEffect, UIEffect, UIEffect, UIEffect, UIEffect, UIEffect, UIEffect, UIEffect, Assembly-CSharp-firstpass, Assembly-CSharp-firstpass, Assembly-CSharp-firstpass, Assembly-CSharp-firstpass, Assembly-CSharp-firstpass, Assembly-CSharp-firstpass, Assembly-CSharp-firstpass, Assembly-CSharp-firstpass, Assembly-CSharp-firstpass, Assembly-CSharp-firstpass, Assembly-CSharp-firstpass, Assembly-CSharp-firstpass, AstarPathfindingProject, AstarPathfindingProject, AstarPathfindingProject, AstarPathfindingProject, AstarPathfindingProject, AstarPathfindingProject, AstarPathfindingProject, AstarPathfindingProject, AstarPathfindingProject, AstarPathfindingProject, AstarPathfindingProject, AstarPathfindingProject, DissonanceVoip, DissonanceVoip, DissonanceVoip, DissonanceVoip, DissonanceVoip, DissonanceVoip, DissonanceVoip, DissonanceVoip, DissonanceVoip, DissonanceVoip, DissonanceVoip, DissonanceVoip, PhotonBolt, PhotonBolt, PhotonBolt, PhotonBolt, PhotonBolt, PhotonBolt, PhotonBolt, PhotonBolt, PhotonBolt, PhotonBolt, PhotonBolt, PhotonBolt, PhotonRealtime, PhotonRealtime, PhotonRealtime, PhotonRealtime, PhotonRealtime, PhotonRealtime, PhotonRealtime, PhotonRealtime, PhotonRealtime, PhotonRealtime, PhotonRealtime, PhotonRealtime, Opsive.UltimateCharacterController.Demo, Opsive.UltimateCharacterController.Demo, Opsive.UltimateCharacterController.Demo, Opsive.UltimateCharacterController.Demo, Opsive.UltimateCharacterController.Demo, Opsive.UltimateCharacterController.Demo, Opsive.UltimateCharacterController.Demo, Opsive.UltimateCharacterController.Demo, Opsive.UltimateCharacterController.Demo, Opsive.UltimateCharacterController.Demo, Opsive.UltimateCharacterController.Demo, Opsive.UltimateCharacterController.Demo, InControl.Examples, InControl.Examples, InControl.Examples, InControl.Examples, InControl.Examples, InControl.Examples, InControl.Examples, InControl.Examples, InControl.Examples, InControl.Examples, InControl.Examples, InControl.Examples, Opsive.Shared, Opsive.Shared, Opsive.Shared, Opsive.Shared, Opsive.Shared, Opsive.Shared, Opsive.Shared, Opsive.Shared, Opsive.Shared, Opsive.Shared, Opsive.Shared, Opsive.Shared, UIEffect_Demo, PhotonWebSocket]

 

I was able to fix this by going to Edit -> Preferences -> External Tools -> Regenerate project files

 

Thanks!! Took me a while to find this