Had R-studio installed, but it stopped working for some reason.
Reinstalled R (version R 3.6.1 GUI 1.70 El Capitan build (7684))
now, when I download R-studio (RStudio-1.2.1335.dmg) and try to open it, I get a warning: The following disk images couldn't be opened: RStudio-1.2.1335.dmg
No such file or directory.
the RStudio-1.2.1335.dmg is 127 MB
In disk utility, I can verify the download as per below
Checksumming Protective Master Boot Record (MBR : 0)…
Protective Master Boot Record (MBR :: verified CRC32 $0CBBDB2E
Checksumming GPT Header (Primary GPT Header : 1)…
GPT Header (Primary GPT Header : 1): verified CRC32 $DE5CB69A
Checksumming GPT Partition Data (Primary GPT Table : 2)…
GPT Partition Data (Primary GPT Tabl: verified CRC32 $C81A7CB2
Checksumming (Apple_Free : 3)…
(Apple_Free : 3): verified CRC32 $00000000
Checksumming disk image (Apple_HFS : 4)…
disk image (Apple_HFS : 4): verified CRC32 $F200AA3D
Checksumming (Apple_Free : 5)…
(Apple_Free : 5): verified CRC32 $00000000
Checksumming GPT Partition Data (Backup GPT Table : 6)…
GPT Partition Data (Backup GPT Table: verified CRC32 $C81A7CB2
Checksumming GPT Header (Backup GPT Header : 7)…
GPT Header (Backup GPT Header : 7): verified CRC32 $EE092B72
Operation successful.