Sync with Zoho CRM stopped working and deactivates by itself

Sync with Zoho CRM stopped working and deactivates by itself

Hi,

why do I have this sync job inactive: 

Sync Description Ports and Line General
Mapped List Name Sea Side Crane Executor
Last Sync Time 25 Aug 2016, 01:00 AM

I can't sync it manually, it gets discarded. Every time I activate it then it deactivates by itself, so I have no contacts synced from for 3+ months by now.

What should I do different?

Evgeny Drokov