Everything was fine with my cluster of two VMs with version 8.6 installed on UCS server.
After one week, the customer asked to change the password for all the users, I logged in to CUCM administration page, and here is the surprise, I didn't fine the BAT tab. I tried to search on the problem but I couldn't find any thing helpful.
Waitiing your support
Strange things happen sometimes
Check your BPS (bulk provisioning service) on your publisher. Is it still running/activated..Maybe you should give it a kick! I.e restart the service
It seems the customer swapped the IP addressing between the pub and sub. and I was accessing the wrong IP.
BAT menue is accessable only from the publisher.