Error with Zoho Mail Suite sync and Outlook 2016

Error with Zoho Mail Suite sync and Outlook 2016

Hi!

I have downloaded and installed the "Zoho Mail Suite Plug-in for Microsoft Outlook 32 bit" from here  https://www.zoho.com/calendar/39746644/ZohoMail-SuiteSync.exe and installed it on a Windows 7 System (.NET 4.0/4.5 installed) with Outlook 2016.

After launching the Plug-In it asks me for Username and Password. I enter them and afterwards nothing happens. The user/pass dialog remains open but unresponsive, I have to kill the "Zoho_Mail_Suite_Sync.exe" in Task-Manager.

I have checked the zohoplugin.log:

  1. [03.01.2018 11:40:46] - Zohobusinessplugin.login : Login - 1.1
  2. [03.01.2018 11:40:46] - Zohobusinessplugin.SREQ : Login - 1.1
  3. [03.01.2018 11:40:46] - get uid 37342659
  4. [03.01.2018 11:40:46] - Zohobusinessplugin.SPACEConfig : starting db config
  5. [03.01.2018 11:40:46] - Zohobusinessplugin.SPACEConfig : is prf db present True
  6. [03.01.2018 11:40:46] - Zohobusinessplugin.SPACEConfig : DB initiation sucess
  7. [03.01.2018 11:40:46] - Zohobusinessplugin.SPACEConfig : EX-CON USER DB MIG-1
  8. [03.01.2018 11:40:46] - Zohobusinessplugin.SPACEConfig : profile calling 
  9. [03.01.2018 11:40:46] - Zohobusinessplugin.otherDLL : vuri path  C:/Zoho/Zoho%20Mail%20Suite%20sync/Zoho_Mail_Suite_Sync.exe
  10. [03.01.2018 11:40:46] - Zohobusinessplugin.otherDLL : dll path 32 C:\Zoho\Zoho Mail Suite sync\redemption.dll
  11. [03.01.2018 11:40:47] - Zohobusinessplugin.SPACEConfig : profile check 
  12. [03.01.2018 11:40:47] - Zohobusinessplugin.login : Login - 1.2
  13. [03.01.2018 11:40:48] - Zohobusinessplugin.util : URL exception  System.Net.WebException: The remote server returned an error: (400) Bad Request.
  14.    at System.Net.HttpWebRequest.GetResponse()
  15.    at ZohoBusinessPlugin.Util.urlAccess(String url, String content, Boolean gets)
  16. [03.01.2018 11:40:48] - Zohobusinessplugin.util : URL exception     at System.Net.HttpWebRequest.GetResponse()
  17.    at ZohoBusinessPlugin.Util.urlAccess(String url, String content, Boolean gets)
  18. [03.01.2018 11:40:48] - Zohobusinessplugin.util : URL exception  System
  19. [03.01.2018 11:40:48] - Zohobusinessplugin.util : Error in check update System.ArgumentNullException: Value cannot be null.
  20. Parameter name: s
  21.    at System.IO.StringReader..ctor(String s)
  22.    at ZohoBusinessPlugin.Util.checkUpdate(Boolean autoUpd)
  23. [03.01.2018 11:40:48] - Zohobusinessplugin.login : Error while login Object reference not set to an instance of an object.
  24. [03.01.2018 11:40:48] - Zohobusinessplugin.login : Error while login Zoho_Mail_Suite_Sync
  25. [03.01.2018 11:40:48] - Zohobusinessplugin.login : Error while login    at ZohoBusinessPlugin.LoginFormNew.SignInBtn_Click_1(Object sender, EventArgs e)

I have tried to intentionally enter a wrong password and this works fine, I get a message that username/password is incorrect. So the basic authentication seems to work.

Any ideas?
Thank you!
ev