[FTS] cbft doesn't delete pindex files when deleting an index after moss crash

After index creation process failed with "out of disk space" error deleting the index from UI doesn't remove associated pindex files from disk. 

The behavior:

After limit is reached switching to FTS index  page throws "unexpected server error" sometimes  (screenshot attached) but no any alerts or detailed error messages shown to the user.

In rest of the cases it shows " Document Count: 0 " w/o any progress.

Deleting the index from UI doesn't remove associated pindex files from disk

I've attached fts.log file.