Error in synchronisation of contacts

My contacts don’t work with em Client 6 after regretting the upgrading to em Client 7. Before the upgrading I had all my contacts from my 2 Gmail accounts, but when I downgraded to em Client 6 there is no contacts at all. I get this message:
"Operations/Errors/An error occurred:
Synchronization of folder “Mymail@gmail.com/Contacts/” failed with an error: Execution of authentication request returned unexpected result: 404 ()"I am in this situation since October or November. I tried to import my contacts from Gmail but it doesn’t work. I don’t like em Client at all, everything is confusing and messier than before. Please, help me in solving this problem.

Hello RL,

We apologize for the inconvenience. In order for us to have a closer look, we would please ask you to go to Menu -> Tools -> Settings -> Advanced -> Logging and turn on logging for the ‘Google Contacts’ for the account(s) that display the error message. The next time the error you are describing pops up, please go again to Logging, click on Send Longs and send them to hester@emclient.com with a link to this thread.

Thank you,
Maurice