macOS

This applies to both macOS Sequoia (15.x) and macOS Sonoma (14.x)

Cannot open PreYarn

Each Release of macOS makes changes to the gatekeeper security feature which may cause issues launching PreYarn, Refer to https://support.apple.com/en-us/102445 for more details.

Below outlines 2 workarounds.

Method 1

Right Click on PreYarn (or press control and click on PreYarn)

Select Open (you may be prompted for your password or fingerprint if you have Touch ID)

Method 2

macOS will show any applications that were blocked for about an hour, to see the apps that have been blocked

open the system settings menu

Scroll down to Privacy and Security Tab, find the section highlighted and press Open Anyway for PreYarn

You may get a prompt for your password or TouchID

Press Open

Rosetta

You may be prompted to install Rosetta depending on the version of PreYarn and the platform (intel or mac silicon)

Corrupted File

Launching PreYarn fails with the following, this is most likely due to the file being corrupted , redownload again or reachout to yarnlab support.