I had a similar issue and managed to fix it "in place" (after doing a complete recovery with R-Studio, as a safety measure), but it involved some in-depth tweaking, no automated program could do anything in that particular situation.
viewtopic.php?f=1&t=36969https://superuser.com/questions/1332970 ... o-fix-themBut there are no two logical issues exactly alike, what worked then might not help at all with your problem.
You could try to open the partition with DMDE and post some screenshots (especially if you see error warnings in red).
Also, just in case, check the drive's SMART status. You should already have a backup if the data is worth anything, but if there's any SMART defect, and you don't have a recent backup, you should be prepared to clone/image the whole drive ASAP, or at least extract non backed-up folders with a good recovery software (if R-Studio can't access the partition then you've got a serious problem – normally it shouldn't be necessary to perform a complete scan, the partition should be listed right away, even if it doesn't have a drive letter, clicking on "Open drive files" should be enough to list the currently allocated files/folders unless the MFT is corrupted).