Consequently, the archive manager will not recognize this as part of the .part4.rar sequence. It will treat it as an orphaned or corrupted file.
Using your file explorer or terminal, rename the corrupted file: RADPA-PGME-ELMG-rsb.part4.ra r
If renaming fails, open the file in a hex editor (HxD, 0xED). Look at the first 7 bytes: Consequently, the archive manager will not recognize this