On macOS 15.1 Sequoia Beta 6 (24B5070a), clicking on SeaMonkey in the Dock displays a dialog window with the Finder icon, an OK button and the following text:

The application “Dock” does not have permission to open “(null)”.

Similarly, double-clicking the SeaMonkey app bundle in Finder displays two subsequent dialog windows with the Finder icon, an OK button and the following text:

The application “Finder” does not have permission to open “(null)”.

This problem was not present with the previous macOS beta, that is macOS 15.1 Sequoia Beta 5 (24B5055e).
I'm pretty sure it started after updating to Beta 6 (24B5070a), without changing the installed SeaMonkey version.

I verified this problem with SeaMonkey 2.53.19 and SeaMonkey nightly 2.53.20b1pre from nightly/2024/10/2024-10-13-21-00-03-comm-253.

Every other app on the system launches just fine.
I tried to reinstall SeaMonkey but it didn't solve the issue.

Same here.
Mac OS Sequoia 15.1 (Built 24B83) with SeaMonkey 2.53.19
Do you have any solution to this problem? It's very important for me please.

(In reply to Ference from comment #3)

Do you have any solution to this problem? It's very important for me please.

You can open Terminal and launch SeaMonkey with this command (assuming the app is in the Application folder):

% /Applications/SeaMonkey.app/Contents/MacOS/seamonkey-bin

A Finder window will pop-up asking if you want to move SeaMonkey to the trash, don't do it and open System Settings --> Privacy & Security, scroll down and select "Open anyway" in the Security section.
Go back to Terminal and launch SeaMonkey again with the above command, now it should let you open the app.

(In reply to Andrea Govoni from comment #4)

(In reply to Ference from comment #3)

Do you have any solution to this problem? It's very important for me please.

You can open Terminal and launch SeaMonkey with this command (assuming the app is in the Application folder):

% /Applications/SeaMonkey.app/Contents/MacOS/seamonkey-bin

A Finder window will pop-up asking if you want to move SeaMonkey to the trash, don't do it and open System Settings --> Privacy & Security, scroll down and select "Open anyway" in the Security section.
Go back to Terminal and launch SeaMonkey again with the above command, now it should let you open the app.

Thanks Andrea,
You are the best.
I'm in.

(In reply to Andrea Govoni from comment #4)

(In reply to Ference from comment #3)

Do you have any solution to this problem? It's very important for me please.

You can open Terminal and launch SeaMonkey with this command (assuming the app is in the Application folder):

% /Applications/SeaMonkey.app/Contents/MacOS/seamonkey-bin

A Finder window will pop-up asking if you want to move SeaMonkey to the trash, don't do it and open System Settings --> Privacy & Security, scroll down and select "Open anyway" in the Security section.
Go back to Terminal and launch SeaMonkey again with the above command, now it should let you open the app.

I submitted the exact same problem and tried many workarounds. This is the only one that works for me. Thank you very much.

I successfully created an Automator app that runs the launch script. It sits on my Desktop (probably could be in the Dock) which I dbl-click on to launch SeaMonkey 2.53.19 in Sequoia 15.1. When you quit SeaMonkey, the script cancels. This is the ONLY way I can currently launch SeaMonkey (i.e., instead of using Terminal as above). It is based on the above address of seamonkey-bin. Don’t know how many users know of these workarounds. For them, SeaMonkey is functionally dead in Sequoia 15.1.

Until apple fixes this (or not) you can work around it by self signing SeaMonkey:

http://forums.mozillazine.org/viewtopic.php?p=14987133#p14987133

codesign --force --deep --sign - /Applications/SeaMonkey.app

The macOS bug that was preventing unsigned Intel apps to launch has been fixed with macOS 15.2.

Thank you for the information. I’ve just updated to macOS 15.2, and I can confirm that SeaMonkey now works as it used to before the update to 15.0.

Just tried SM 2.53.19 on OSX 15.2 (24C101) with Darwin 24.2 and can confirm that this issue is no longer present.

I tested the upcoming 2.53.20b1 with macOS 15.2 and it seems that Apple indeed did fix it. I put a short info in the upcoming beta news.

Still keep in mind that we are short on resources and will not test future beta versions. If you are unhappy with this look for another browser or contribute. If it can be fixed on our side we try but this one wasn't from the start.

If you upgrade I advise you wait at least for a .1 release. Apple has broken us numerous times lately with major releases. And in this case even with a point release.