safari can't establish a secure connection

I thought this was a likely explanation as well...but it doesn't explain why I can still access certain PKI-enabled MS SharePoint sites from my iMac and not from my MBP.

I access two US Government PKI-enabled MS SharePoint sites, both administered by separate domains. I am able to access both MS SharePoint sites on my iMac - yet when I try to access both from my MBP, only one is accessible. So I think it is safe to assume that security protocols are not the issue with me. Both Macs are running the latest OS X are up to date.

Deleting the Cache.db file and removing all website data didn't work. The Firewall doesn't seem to be affecting the site - I have turned the firewall off and tried to access the site, and it didn't work.

OMG I finally fixed my problem with this!!!

I had this come up for the past 4 days and have searched EVERYWHERE to find out how to fix it. I then found a suggestion and thought "i've literally tried everything so why not" It said that my date and time might be off and to turn on auto date and time in the General Tab on my iPad (iOS 10.0.2). I did it and it was fixed!!!! I was so frustrated reading the Apple support questions with no help to my proble. So I REALLY hope this helps someone!

Hey that saved my bacon,

I tried all the usual resets,cache emptying etc,but still I couldn't get onto several key websites for me on Safari.

Then I saw the post about disabling web-shield on Avast and everything now works!

So a billion thanks to Incognito Cube!

I wonder if one can turn it back on again in the future?

Thanks the web shield was the issue. I disabled it and now everything works!!!

I review the whole post on this subject. Nothing helped. :-(

"Can not connect to the server" message on each browser including Approte :-(

Mac Pro just upgraded to ElCapitan :-( as a result few apps do not work (VMWare, Apperture ... as most important to me)

I tried to get update for Apperture and .. failed. Appstore can not connect to the server. None of the browser can nonnect using SSL.

Basically dead in the water.

I had Norton Security installed - removed the whole application. - no help

I do not have any other AV software. I am going crazy here.

btw. the same network settings are on my laptop MacBookpro and there is no problem at all.

Please help

Greg

Same here. can't figure this out! did you manage to solve this?

Thanks!

-- amir

Avast causes problems. I suggest you remove it.

Avast

Avast Un-install

You really don't need an anti-virus program on a Mac. This one is one that operates fairly well with Macs.

ClamXav

i just disabled the avast web shield and everything is fine now ! thanks !

Be safe - see my longer answer in this thread from today.

Uninstall all your anti-virus software using the developer's uninstall instructions. The software isn't needed on a Mac and often hurts the computer's performance.

Avast

Avast Un-install

AVG Uninstall

yyes, this was spot on and everything is working fine now

Thanks Eric, but none of the suggestions in the links worked for me.

I should also add that exactly the same thing is happening in Firefox, with the message "Secure connection failed".

I use Sophos and This solved the problem immediately - thank you so much!

This has been annoying me for weeks!