IntelliJ IDEA can't open projects or add SDK on macOS Catalina
It's a known issue specific to the recent macOS Catalina update. Please follow YouTrack ticket for updates.
You can also help by providing the following information in YouTrack:
Open the file chooser, select a directory (but don't open it yet), take a screenshot, then open a directory; then attach idea.log and the screenshot (a path to a project and a time of the operation are needed, too, but they should be guessable from the screenshot).
As a workaround until this issue is resolved you can add -Dide.mac.file.chooser.native=false in Help | Edit Custom VM Options and restart the IDE.
Mac OS, Mojave or Catalina, Exit intellij first,
- Apple menu > System Preferences, click Security & Privacy, then click Privacy.
- Click the lock , then enter your administrator password.
- From the list of items on the left, select Full Disk Access.
- Add Intellij(or other whatever app having this problem) to the apps allowed full-disk access by using the add button.
Lock and try again.
Hope this will help.
Ref from apple support of other things, but I tried, it works!