After using the embedded hdr function to create an hdr of 3 raw files in LR6.2.1 the new dng fails to appear in the library. The dng is on disk and can be opened in Elements. Attempts to manually import it into LR are unsuccessful as the import wizard claims the dng file from the hdr function is already imported. Tried with two sets of raw files with the same result. Other hdr dngs have successfully completed in the past, including earlier today.