virtualbox.org

I've been running VB for years on my Windows 7 machine without a hiccup. All of a sudden I upgrade to Windows 10 and my VMs start randomly giving me errors. Sometimes they start, and other times they don't and spit out errors.

Then on top of that, I just noticed that I'm not running the latest version. VB used to tell me on startup when there was a new version, but apparently at some point that stopped. I'm on 4.3.30 and see there's now a 5.0.4 version. But to make matters worse, I see that Windows 10 isn't officially supported (what's up with that?).

Is it safe for me up install 5.0.4 over 4.3.30, or should I just stay where I am until there's an "official" Windows 10 version?

Couple of things that may have slipped by you:
Windows 10 is not yet officially supported as a host. They're working on it but it's not running solid yet. When they get Virtualbox to run well, then they'll likely mark Windows 10 as supported.
I've read that there's a glitch in the update announcer that doesn't tell there's a new version of Virtualbox available. They're working on that too.
I've also read that for major version updates, like from 4 to 5, do an uninstall first, then install the new version.

Yeah I saw that Win10 isn't officially supported. Thanks for the tip about uninstalling 4 before going for 5. I'm almost at that point.