@maracles Maybe it is something to do with the gateway or data refresh and data is not getting returned back to service which is causing visual to fail. To troubleshoot I would suggest,
1. Start importing less number of columns and filtering out data so that only small amount of data is required. Then publish and refresh. This will help figure out if the problem is with data being returned or not to the service. Also each time import fields that are different from previous test to see if the problem is with certain fields or not.
My feeling is that since you're using personal gateway maybe certain type of column and data within is causing it to fail. I am not 100% sure but i think i've seen before where someone complained about specific type of column with personal gateway.
Anyways doing above will atleast give you some insight and maybe even solve the problem. I would also suggest you publish with using data gateway instead of personal gateway.