Is it possible for you to share a packaged workbook (.twbx) that shows what you're working on? Seeing the data really can make it easier to determine what's happening. My thought in the meantime is that you could disaggregate the data or change it to a dimension form a measure ( Disaggregating Data) perhaps changes to how data was interpreted in 10.0 or another version just switched the default.
Unfortunately it is sensitive data which I am unable to share in public. Given data set is quite large it is not easy to randomize and customize it for public domain. I need to find a way to generate dummy data set for this.
Nevertheless, I was finally able to figure out why this was happening. My data set spans over certain period of time and timestamped. Apparently level of details in time domain at desired time granularity was missing from the marks card that needs to be added. Once this is added detail paths reappeared again, otherwise tableau seems to use only one or a few samples of the data rather than the full set or bigger set depending on desired interval or granularity period.