The project is selected from the initial interface, the dialog disappears, and then nothing. Eventually I kill the Unity process.
It seems like taking an out asset out – any asset, the slightest little unused texture – can convince it to open it when next attempted.
The project this is occurring is big and complex. Well, for me, anyway.
Other than that I’ve been delighted with the beta progress + performance! Keep up the great work Unity team! You guys are enabling great stuff!