Safari says it cannot open because it doesn

1 - Suggest restarting in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal.

2 - Does the issue present in this mode ?

3 - If not - there could be something in the main User Account playing up. To further isolate this - Set up users, guests, and groups on Mac. Then log out of the Main User account and log into the dummy account and test again if the issue persists.

4 - If the issue is present in the dummy account - then this appears to be a System Wide issue.

Are you running any VPN, Anti-Virus, or Cleaning apps?

Go on the Apple certificate page:

Apple PKI - Apple

Download the Apple Intermediate Certificates

Apple IST CA 2 - G1 Certificate (direct download)

Double click the downloaded certificate to install it in Keychain Access.

You should see it now, in login certificates.

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See if you have unknown Profiles.

To remove a configuration profile in macOS:

1. From the Apple menu, select System Preferences....
2. From the View menu in System Preferences, select Profiles.Note:
3. Profiles won't be visible until you have at least one profile installed.
4. Select the profile you want to remove, and then press the - (minus) button. Click Remove to remove the profile.
5. softwater

User level: Level 5 (5,557 points)

Feb 16, 2020 3:04 AM in response to sukwaria

If your browser prefs are locked down, you'll probably find the reason in System Preferences > Profiles. 

Remove all profiles you don't recognize, then run something like DetectX to clear out the persistence agents. 

https://sqwarq.com/detectx/

Disclaimer: DetectX is a utility I develop; you do not need to pay for it to use it to use it. It does not collect your data or require any form of subscription/login.

Start with this...

Safe Boot, (holding Shift key down at startup), does the problem occur in Safe Mode? Could take 10 minutes or more.

Safe mode attempts to repair Disks & clears lots of caches & loads safe Drivers, & prevents loading of 3rd party extensions, so if Safe Mode works try again in regular boot.

I’m having the same issue. I tried running in safe mode and safari wouldn’t open. Just updated my 27” intel iMac to safari 15.4 and os 11.6.5 earlier in the day.

I have the same problem when I use safe boot.