Problem on Unity export

Hi,
i am a french student in high who will do an intern ship in a company which works on Hololens (excuse for my english, i could write some mistkakes sometime). I follow this microsoft turoial : HoloLens (1st gen) Basics 101E - Complete project with emulator - Mixed Reality | Microsoft Learn and i am blocked at the first step, i don’t arrive to export my unity project to try it in the hololens emulator on Visual Studio. Unity saies to me that there is a problem in the compliator. Do you solutions ?

Thank you,
Pierre-louis

Restart Unity and build again. It should print actual errors of what’s wrong.