After upgrading to macOS Big Sur I couldn’t run Oracle SQL Developer. I got the following error: The application “SQLDeveloper.app” can’t be opened

To resolve this issue I got help from Kris Rice and Niels de Bruijn. The issue is caused by Apple and the Java applet plugin.
Here’s how I got SQL Developer working:
List your Java Versions
1 | /usr/libexec/java_home -V |
The one that caused the problem is the "Oracle Corporation" - "Java" /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home
and you’ll need to remove it.
Remove the Applet Plugin
1 | sudo rm -rf "/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/" |
If you run SQL Developer now it should work. I’m not sure about the side effects of removing this Java applet plugin. If I find it to be critical to other things I’ll be sure to update this post.