Thank you all for reporting the same issue.
I was concerned that I had the same issue on two different laptops with different OPs.
However, when I tried Clipchamp just now, it opened and is working as usual.
It seems there was something in Clipchamp update perhaps on 12 June that cause this widespread problem.
I am so glad now it is working.
Nonetheless, may I urge Microsoft Clipchamp team to provide some sort of 'contact' outside of Clipchamp to report such incidences in the future? I found on they webpage an email to contact (******@clipchamp.com), but this email bounced back immediately: I don't know why they have it on their website! All my research to find a way to contact Clipchamp recommended to 'log-in > open Clipchamp > go to help/chat widget' - which wasn't possible given that Clipchamp was opening in a white page!
Any way, I am glad the issue is now solved :)