Image attachments are displayed as Unknown Attachment after moving page tree to other space

Bug Summary:

• Image attachments displayed as Unknown Attachment after moving page tree to other space

Environment:

• Confluence 6.5 Linux 64bit, PostgreSQL 9.5, Google Chrome 63.0

Steps to replicate:

1. Create new page "testapge"
2. Create new nested page "nestedtestpage"
3. Go to "testpage", enter edit mode
4. Add new page layout (two column section)
5. Add image attachment within layout section.
6. Click on the image -> Edit link
7. Add link to nestedtestpage
8. Move "testpage" page tree to different space by using "..." -> move

Replicaiton steps recording
5i37tRkMOl.mp4

Expected results

Image link will be visible on new space/page

Actual results

Image attachment is displayed as "Unknown attachment"

Workaround

1. Copy page tree to other space by using "..." -> copy
2. Remove previous page-tree