Clonezilla not able to mount drive

I have a machine where I want to create a clone of the primary disk and save it on a secondary (internal) disk. After a little reading, I decided to try Clonezilla Live, but I'm running into the strangest error and have no idea why.

1. After starting up and choosing the keymap and the like, I choose "device-image" to save an image of a drive.
2. I then choose "local-dev", since I want to use an internal device.
3. It prompts me to plug in any USB devices and press Enter. I just press Enter since I don't want to use this.
4. Clonezilla informs me I need to choose a disk to mount as /home/parimag. I'm presented with 2 disks to choose from. One is the disk I want to clone (sdb1 with an NTFS partition), and the other is where I want to save the image (sda5 with a FAT32 partition). (Please don't ask why the drives are assigned those letters and numbers. This machine was given to me like that.)
5. I choose sda5, the FAT drive.
6. I'm prompted to choose a directory for the Clonezilla image. I'm only presented with "/ Top_directory_in_the_local_device", so I press Enter to select it.
7. I then see the following error:

Clonezilla image home directory /home/partimag is not a mounting point! Failed to mount other device as /home/partimag!

I'm then given the option to continue anyway, but I don't know what will happen if I do. This doesn't really give me much information about what the problem is. I would appreciate any insight.