429 Too Many Requests

If deleting preferences, as Matti recommended, is not enough, I suggest you delete the application and download a fresh copy from your list of purchases in the App Store (click your account at the bottom left).

And yes, do follow Smilin-Brian solid advice and do not use any third party antivirus or "cleaners".

Opening Compressor using the Option-Command keys worked! Compressor opens now. Thanks!

The usual FCP and Compressor troubleshooting is to open them with Option-Command keys so their settings are resetted to defaults. I'm booted to Tahoe so I can't test Compressor in GG right now.

Welcome and thank you for reaching out. 🤗

If you have any antivirus software installed, then remove it A.S.A.P. as they interfere with the system operations and performance.

If you don’t have anything like that installed, then try the following:

First, let’s see if this issue happens in Safe Mode:

1. Shut down your Mac.
2. Press and hold the power button on your Mac. As you continue to hold the power button, your Mac turns on and loads startup options. When you see Options, release the power button.
3. Select your startup disk. It's named Macintosh HD, unless you changed its name.
4. Press and hold the Shift key, then click the “Continue in Safe Mode” button below your startup disk.
5. Log in to your Mac. You might be asked to log in again.

If the strange behaviors do not occur, then it may possibly be a software issue.

If the issue doesn't continue in safe mode:

Leave safe mode by restarting your Mac normally, then try to reproduce the issue.

If the issue doesn't return, it might have been resolved by the other things that safe mode did at startup, such as checking your disk and clearing caches.

If the problem persists, then let’s try this:

• Software Update.
• Use Apple Diagnostics to test your Mac.

Need more help?

• United States: 1-800-APLCARE.
• Contact Support.
• Mac Support.
• Mac User Guide.

Good luck! 👋🏼😉

Smiliñ 😎 Brian | Community Volunteer

Matti Haveri wrote:

I'm booted to Tahoe so I can't test Compressor in GG right now.

I now dual-booted from Tahoe to GG (...I might soon upgrade also my internal disk to GG because all my mission critical apps work OK there) and Compressor 5.3 launches there OK.

Working perfectly fine here in GG, so it's not universal. But yes, macOS 27 and iOS 27 seem to have introduced a bunch of odd bugs. Let's hope there's an update soon.