1. Double-click the downloaded installation file.

2. Move R-Studio.app to the Applications folder

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3. Go to Applications in Finder and double-click R-Studio.app to start the program.

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When you start R-Studio for the first time on macOS High Sierra and higher, a System Extension Blocked warning message will appear.

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At the same time R-Studio will throw its own message:

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If you need access to your system disk, click the Open Security Preferences button on any of the messages, go to the Security and Privacy preferences, and click the Allow button.

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R-Studio will start with full access to your system disk. You need to follow this procedure only once, next time R-Studio start without this message.

If you don't want to unblock R-Studio, click the Exit button on the R-Studio's message. R-Studio will start and work properly, but without access to the system disk and when you start R-Studio next time, its message will appear again. You will be able to unblock the program if needed.

1. Go to Applications in Finder, control-click R-Studio.app, and select Move to Trash.

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1. Upon receiving the email with the Registration key, open the attachment, then select and copy the key.

2. Click the R-Studio menu, select About R-Studio, then select Register.

3. Enter your registration information and then paste the Registration key. Do not try to type it manually.

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4. Click the OK button.