No entry sign on start up

Birdvid_57 wrote:

To be clear Leroy, the problem started with an upgrade to the latest version of Catalina. It seems to be more of an issue with the new version of Catalina and late 2012 iMac rather than anything to do with Lightroom.

Boot into SafeBoot mode—

delete Lightroom reboot and test.

 —Try a SafeBoot https://support.apple.com/en-us/HT201262

Takes noticeable longer to get to the login screen, does a 5 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache,  etc. 

Login and test. Reboot  as normal and test.  Caches get rebuilt automatically.

In Safe mode third party system modifications and system accelerations are disabled, it removes malware, etc hampering smooth operation, however a  reboot will put it back to normal mode.

This test will tell you if third party interference; extensions etc are not loaded in safe boot mode. 

 —Test issue in another user (or guest user) account https://support.apple.com/guide/mac-help/set-up-other-users-on-your-mac-mtusr001/mac

  This will tell you if it a universal issue or isolated to your user/admin account. 

Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus

Birdvid_57 wrote:

No entry sign on start up

I’ve been running Catalina on a late 2012 iMac for some time. During the last update I was informed that the update could not be completed because of a kernel cache issue. On restarting the Mac I was presented with the no entry sign suggesting that the OS was not compatible. I opened in the Mac in Recovery mode, repaired the disk and tried again to reload the OS (automatically it tried to download Catalina). Again installation failed due to a kernel cache issue. I opened again in Recovery mode and this time erased the disk opted for a clean install. Catalina loaded ok with the latest update and all seemed well. However on trying to access some files on Lightroom I was presented with the wheel of doom and the Mac then crashed. It would not restart and I was presented again with the no entry screen. Clearly Catalina does work on this Mac configuration so does anyone have any idea as to what is going wrong?

If your Mac starts up to a circle with a line through it

https://support.apple.com/en-us/HT210901

Birdvid_57 wrote:

Yes I know that and have followed the advice as my question stated. However the advice leaves it at saying that the OS is incompatible with the device, which isn’t the case here as it’s been running Catalina for at least a year.

With the release of macOS 10.15 Catalina, applications will have to be 64-bit. App developers will issue updated apps if they want their apps to work on this newest macOS upgrade

Lightroom Classic and macOS Catalina (10.15) - Adobe Help ...

Lightroom and macOS Catalina (10.15) - Adobe Help Center

Lightroom and macOS Catalina 10.15 Compatibility

https://helpx.adobe.com/x-productkb/global/fix-macos-64-bit-compatibility-errors.html

https://www.adobe.com/products/photoshop-lightroom.html

Birdvid_57 wrote:

However on trying to access some files on Lightroom I was presented with the wheel of doom and the Mac then crashed.

Once I had done a clean install of Catalina I then downloaded Lightroom, so presumably got the latest version. It loaded ok and only caused problems when I tried to access an old photo file.

It's not clear from your response whether you’re suggesting this a Lightroom issue?

thanks

If this is isolated to your third party software, then yes I would suspect it is a LightRoom issue.

https://helpx.adobe.com/lightroom-cc/kb/macos-catalina-compatibility.html

Contact the Developer for Support/Help/FAQ/known issues/compatability