Safari won't open

Try setting up another admin user account to see if the same problem continues. Please post back on whether or not this worked. Also try the Safe Mode. Please post back on whether or not this worked.

Isolating an issue by using another user account 

Safe Mode - About

If it works in the Safe Mode, try running this program when booted normally and then copy and paste the output in a reply. The program was created by Etresoft, a frequent contributor.  Please use copy and paste as screen shots can be hard to read. Click “Share Report” button in the toolbar, select “Copy to Clipboard” and then paste into a reply. This will show what is running on your computer. No personal information is shown. If the log won’t post, try posting it in Pastebin and provide a link in a reply        Pastebin

Etrecheck – System Information

Try booting into safe mode: Hold down shift at the chime, unless it doesn’t chime on you Mac - Hold down shift at the Apple logo

nfejohn wrote:

...all the recommended restarts and clear history.

Don't forget to clear the cache as well. To do so...

1. Open: Safari
2. Unhide: The Develop Menu
3. Go To: Develop Menu
4. Select: Empty Caches

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RESET YOUR SMC and NVRAM

Sometimes, changes are made that result in user/device interoperability becoming an issue of sorts. So, perform both of the following:

• Reset the SMC
• Reset the NVRAM

You are welcome. Easy fixes are always nice.