Unused images not deleted

Hi,

I have the following list of images that are unused:

REPOSITORY            TAG                 IMAGE ID            CREATED             SIZE
gitlab/gitlab-ce      <none>              fad0a00dde08        6 days ago          1.91GB
portainer/portainer   <none>              62771b0b9b09        13 days ago         79.1MB
alpine                3.7                 6d1ef012b567        17 months ago       4.21MB

I want to delete them but am unable to

Error: No such image: alpine
I get the same from Portainer. The images cannot be deleted:

image

Do you have any advice? I don’t think they are taking up space anymore but I’d like them gone.

I had to delete the unused sha files inside

/var/lib/docker/image/overlay2/imagedb/content/sha256