Hexagon Geospatial has recently completed work on a Hotfix for ERDAS IMAGINE 2016 v16.1 to address the issue of the altered Sentinel-2 formatting introduced by ESA late last year. If you would like to utilize the updated software in order to be able to directly read the updated format please visit the Download section of our website:
Note that using the direct-read capability avoids any decompression / recompression issues associated with the original JPEG 2000 encoded data.
Please also remember that Sentinel-2 images consist of a mixture of differing pixel resolutions. These can be accessed at their native resolutions (and in different groupings) through use of the Sub-Images tab of the File Chooser when opening the SAFE dataset.