Hi @Thomasik, I hope you're doing well!
Is this video in your account, or in a shared link?
Also, am I safe to believe that you're using our website to download the file? If so, feel free to either try an entirely different browser, or clear your current browser's cache, and try an incognito mode too.
Just so we can check if this is a browser-specific problem, or something different.
Keep me posted, and we'll take it from there!