I am able to successfully create contacts in my client from Zoho Mail contacts list (load into the client the contacts from Zoho); however, I am not able to add contacts from my client, and I am not able to edit contacts from my client and have those additions and/or edits synchronize to Zoho..

Client is Thunderbird using Cardbook (Sogo does not work -- will not load contacts from Zoho).

Error example (snippets from logfile) :

When trying to edit contact:

2017.02.25 09:14:07:210 : TC-Zoho-Online : Contact Zfirst1  Zlast1 failed to be updated on server (url : https://contacts.zoho.com/carddav/name@domain.com/default/contacts/910936000000048001.vcf, status : 500)

When trying to add contact:

2017.02.25 09:14:08:802 : TC-Zoho-Online : Contact Firstname1 Lastname1 failed to be created on server (url : https://contacts.zoho.com/carddav/name@domain.com/default/contacts/c84dedcb-fe51-4028-bb3c-48858ac5d80d.vcf, status : 500)

So in short, I am only able to use CardDav to initially load contacts, but not add/edit contacts.  So not very useable. A solution and/or troubleshooting procedure would be VERY helpful.

Is this an issue for others as well?

What are other people using/doing to synchronize contacts to/from Thunderbird / Zoho?

Thanks,

Todd