Will not Synchronize

Using Anki for 18 months now and no prob until recently. I had the latest Anki Desktop edition then after several synch failures reverted to an older version but still had the same result: " A network error occurred: Error details: error sending request for URL(): error trying to connect: Unexpected EOF during handshake". I don’t get this error on my mobile but the changes I’ve made on my Anki desktop are not reflected on my Anki mobile.

If you use your phone as a hotspot and sync through that, or test on a different wifi network, does that help? If not, it’s possible antivirus/firewall/proxy or VPN software on your machine is to blame.

Thanks for the response Damien, I’ll go through the possible causes.