Converting RAF files to DNG

Normally I put my card in my laptop fire up LR and convert my Fuji RAw (RAF) files to DNG, but sporadically it seems to stop, so I then end up having the RAF imported which clogs memory.

I have tired to then move the RAF files into a secondary folder and reimporting them (NOT selecting each photo but the folder), and still they dont convert in light room.

Driving me nuts, as it can sometimes be a few photos in a file or a whole batch

Rather annoying and time consuming...

any help?