Installation under macOS

Gatekeeper quarantine issue with certificate

Although our app is code signed and apple certificate is up to date, we sometimes run into issues as shown below .

Explanation

When you download a file with a browser, the browser will attach a com.apple.quarantine attribute to it, indicating that it came from an untrusted network source. Other types of internet apps (email, chat, etc) should also attach this attribute to downloaded files.

But not all network download methods will apply the quarantine attribute. For example, copying a file over a file sharing connection (e.g. AFP or SMB) with the Finder will not mark it as being in quarantine. Also, command-line tools like curl and wget won't apply quarantine.

Quarantine is a result of the app (or the disk image it was in) being downloaded.

In this case, when you download the .dmg file, it gets marked as quarantined; when you open it, the attribute gets propagated to its contents, so the app is also marked as being in quarantine.

The solution

There are two types of solution to fix this issue.

Solution 1(Preffered) :

Unmount the dmg file
open the terminal and execute the following command

xattr -d com.apple.quarantine </path/to/file>

now remount the dmg file and you should not see the warning any more and the wizard should pop up as shown below

Solution 2 :

Mount the dmg file and open it you should get the error screen as below. click ok

Go to system Settings serach for security and you should see your application was blocked from use … click on Open Anyway

Now it amy ask for a password, enter it and click on Unblock

Now the next screen would appear. click on open

Now the installation wizard should appear