"steam_osx" is damaged and can't be opened

[gib88]

Hello,

We are trying to download steam to our Mac Big Sur, but when we double-click on it to start it, it always gives us the message "'steam_osx' is damaged and can't be opened. You should move it to the Trash."

Steam is a well-known and trusted game hosting service and there should be no reason not to trust it. My google searches reveal that this message comes up not only when the file is damaged but when the OS doesn't trust it. My google searches say the security settings can be lowered to allow the application to run (setting Allow apps downloaded from: to "Anywhere"):



We also tried updating the OS, rebooting, deleting the app and redownloading it, but none of these seem to work.

How do we get around this issue so that we can start playing Steam games?

Thanks

 

[Rod]

It's not advisable to lower security settings to "Anywhere", "App Store and Identified Developers" will work just fine for Steam.
How did you uninstall the version of Steam that you had originally? It's likely there are many associated files that came with that version and some of these may be seen as "damaged" on Big Sur if they are for an earlier macOS or version of Steam.

The best source of information on this topic will be from Steam Themselves; macOS on Steam
From this page I went to support, entered Uninstall and that took me to this page; Uninstall Steam - Steam Support

As you can see the process to uninstall Steam is a little more complex than just dragging the app to the trash.
I strongly advise you follow their instructions to Uninstall first then try downloading a fresh new version from the first page I linked above.

I have Steam running on my MBP running Big Sur so I can assure you it works.

 

[Raz0rEdge]

You should leave the security setting at App Store and identified developers. If you launch apps that didn't come from the App Store or weren't from identified developers and you STILL want to continue, you just return to the Security and Privacy screen and you'll see a new entry at the bottom for the app that was recently blocked and you have an option to "Open anyway". This is the right way to open apps that fall outside of that restriction.

As Rod said, ensure that you are got the Steam installer from Steam directly and it should work fine as I have it on my Big Sur machine as well and it works without issues.

 

[ferrarr]

What Mac do you have? What macOS is it running?

 

[gib88]

Thanks everyone for your help. I deleted Steam using the appropriate method and then installed it again from the official site. This time it seemed to work. Thanks!

 

[Rod]

Woohoo! Happy gaming.