Hi !

Thank you for this post :)

I have similar problems, meaning my zotero 5 standalone cannot sync at all : it gives me the following message (translated from french) :

When I enter my id and password in the parameters, I get this popup message :

There was a SSL certificat error while connecting to api.zotero.org

And after this, if I look at the sync button in the main zotero windows, it displays an error button with something like "Zotero sync server did not accept your ID, please check these informations bla bla bla".

The thing is I checked it like 30 times for the last 2 days on my laptop, on my phone, on my office computer, and it works everywhere : chrome opera, mozzila, edge as well as on the Firefox modules.
The only place where it bugs is Zotero5 :/

I even tried to change my password for a text and numbers only (As a french I had accent -letters as well as special typo, so I tried a simpler password, no result ...)



Thank you in advance for your help :)

Are you using any sort of security software on your computer or connecting to the internet through a proxy?

So what does it say when you load https://sync.zotero.org/ in your browser?

For both site I get a "Nothing to see here." answer when I type it in the address bar.

Both with chrome and Mozzila...

Before I continue, I just want to precises these 3 points :
(1) My zotero application 4.0 works just fine on firefox,
(2) My standalone work with a different folder to avoid problems of compatibility with the FF module 4.0,
(3) I checked my Kaspersky parameters and everything seems to be fully authorized for Zotero standalone


The certificate is as follow

Edited for :
CN = *.zotero.org
O = "not part of the certificate"
OU = "not part of the certificate"
Serial = 31:84:B1:01:DF:CE:7F:A2:90:B1:AD:D8

Edited By :
CN= Kaspersky Anti-Virus Personal Root Certificate
O= AO Kaspersky Lab
OU = "not part of the certificate"

Validity period 29 october 2016 to 3 november 2018

Numeric prints
SHA-256= 93:0D:48:20:4F:6F:D9:F9:D7:E2:A7:D4:1A:13:43:36:B8:59:29:26:EA:B9:E4:7B:27:F6:DF:CA:DA:97:8C:B0

SHA1 = BE:58:79:7F:63:17:83:09:55:57:61:E4:AB:B8:09:45:E3:9D:FF:4E


Now, I am not sure whether or not this certificate that I obtained using my web browser is the same as the one used by the standalone application ...

Is it possible that some kind of conflict exists due to the different languages ?


Thank you for your answers and your time :)

Thank you for your help !
This SSL tutorial seems good and complete :)
I tested some of the propositions but not all .
I will try the following and see if it works :
-from another network (I suspected it might come from the use of a 4G USB smartphone link but didn't get a chance of testing another network).
-Going through my kaspersky settings to see if it does the trick ...

See the page that adamsmith links to.

here are the instructions linked from that page: https://www.zotero.org/support/kb/cert_override
you may need to enlist IT to get you set-up -- they force you on the local certificate and we can only supply limited support for this.

I'm afraid there's no reasonably easy way to do this without Firefox. You'd have to find a way to generate the cert8.db and cert_override.txt files for the certificates forced on you by your institutions. There are tools for this, I believe, but they're pretty involved and beyond the scope of what we can support here. You should get in touch with your IT and get them to help you. After all, they are the ones breaking your SSL connection.

I have the same problem.

Firefox works. But in the Firefox profile directory I can't find a cert8.db, key8.db file to copy to the zotero profile, but only a cert9.db, key4.db.

How can I handle this problem. Is it possible to generate from FF60 a cert8.db file or to adapt zotero5 to use a cert9.db file?

Thanks for help.

Thanks for this hint.