Attention

August 2023 update: osu! Wineskins for macOS, osu!macOS Agent, and this osu!mac documentation website is no longer officially supported or maintained. Official support will no longer be provided by the authors of these respective projects on the osu! forums. You can read more information about this change from Technocoder and aidswidjaja. Thank you for everything.

osu! cannot be opened because the developer cannot be verified

This article is applicable to the following wrappers:
• slc’s Wineskin for macOS 10.14 Mojave and earlier
• Technocoder’s Wineskin with macOS Catalina 10.15 support
• Technocoder’s unofficial Wineskin for macOS 10.14 Mojave and earlier
as well as Technocoder’s osu!macOS Agent program

Behaviour

Your Mac displays a warning saying one of either two messages:

“osu!.app” cannot be opened because the developer cannot be verified.
“osu!.app” can’t be opened because it is from an unidentified developer.

Cause

To directly quote Apple’s support article:

If you try to open an app that isn’t registered with Apple by an identified developer, you get a warning dialogue. This doesn’t necessarily mean that something’s wrong with the app. For example, some apps were written before developer ID registration began. However, the app has not been reviewed, and macOS can’t check whether the app has been modified or broken since it was released.

Resolution

Locate osu!.app in Finder
Right-click (or hold the Control key while clicking) on osu!.app
Click Open

On the dialog that reads:

“osu!.app” is an application downloaded from the Internet. Are you sure you want to open it?

Click Open.

If that didn’t work

There could be something else going on here, and performing basic troubleshooting should help you get to the bottom of it.

If you’re still not sure what’s going on here, copy any osu! crash logs and generate a report with osu!macOS Agent, then let us know on the forums with what we can help.