For RTD 1.5 and backfill to work on nest 3.16 version (I use 32 bit OS), we need to login/launch Nest Plus (From top menu bar "Nest Plus" item) first everytime after logging to Nest terminal for backfill. RTD will work fine either way. After that, we need to open any one of the scrip chart (Shift+P). After that, open data table by right clicking on this this chart<< Data Table. After this, u can start ur backfill as earlier used to do. Working fine. As i am not using 64 bit system, i am not aware of the issues/ solution. May get on to work further if i get its source code.
Thx