Delete Comments built-in script preview throws error for Anonymous created comments

Steps:

1. Go to Bulk Delete Comments from One or More Pages built-in script
2. Choose a space
3. Select at least one page that has comments created by anonymous user on it
4. Choose minimum age of comments
5. Click Preview

Result:

You get the following error instead of a preview of the selection.

Error: Cannot get property 'name' on null object

(Full error attached)

Notes:

The preview should show the number (count) of comments that will be deleted in the selection.