Without your decision, it has no idea what to do. It cannot determine how large your image will be (compression is different for DATA types on the imaged volume) so it needs guidance. It can't stop in the middle of an image to notice it will run out of space, then make an independent decision on deleting your only existing image... if it does this and the balance of the imaging fails then you have no backups at all, not a good place to be.
It really needs guidance. If you only want (1) FULL image you need to tell it that (under "Backup Schedules" you select FULL retention with Keep = 1 BACKUP... this will require space for <2> backups because it will not delete the 1st one until the 2nd is successful) . If you take different image styles (Full, Diff, Inc) you need to tell it how many you want to keep of those as well.
This is not something any imaging app can guess at very well.
It really needs guidance. If you only want (1) FULL image you need to tell it that (under "Backup Schedules" you select FULL retention with Keep = 1 BACKUP... this will require space for <2> backups because it will not delete the 1st one until the 2nd is successful) . If you take different image styles (Full, Diff, Inc) you need to tell it how many you want to keep of those as well.
This is not something any imaging app can guess at very well.