Version 6.4.4

Under Remove a Graemlin there is a red x appearing as a graemlin. This was an image that was added and I believe had a special character in it. When I tried to remove it I get the following message.

“Unable to remove the graemlin from the graemlins directory. Please check permissions on the files in this directory and try again.”

I have checked and reset all permissions. Problem still exists.
I deleted all graemlins from the images/graemlin directory. Problem still exists.

I tried Edit a Graemlin and the markup string from this graemlin is present. Changing the markup results in no change.

The image is definitely not in the images/graemlin directory. The red x also appears under instant graemlin in post and reply.

How can I remove this red x/graemlin?