Index is cleared after rebuilding from Sitecore
Every time i rebuild the index from inside Sitecore, i can see that index is being built in CES administrative tool, then after 10 seconds it get cleared.
I have installed these versions:
Coveo for Sitecore 72 3.0 (784)
Coveo Enterprise Search 7.0 x64 (7104) for Sitecore
This issue has been investigated by Coveo support and it seems to be caused by a time mismatch between the Coveo and Sitecore servers. A different timezone is not a problem but if the time on one of the two servers is changed manually, this issue will appear.
It will be fully supported in December 2014.
It means something goes wrong on the Sitecore side. Can you take a look at your Sitecore logs (starting with log*.)? They must be full of errors.