that looks strange but did you make sure you have the create pages permission?
Also this checkboxes are not there if there are no child pages and/or no attachments to the page.
Can you confirm both is present in the space you are seeing?
thank you for your reply.
As shown 1-1, can’t select multiple pages here?
The following are the problems I encountered
As shown 1-2，single page and contains pictures，It can be checked.
As shown 1-3，I want to choose to copy this parent page and include all the following child pages.Parent page does not contains pictures，It cannot be checked.
The above is my confusion.
I have re-checked now on my Confluence instance.
As for your screenshots that translates to:
1-2 is a single page and according to your information it contains at least one attachment why the "Include attached files and images" checkbox is offered to be checked.
Screenshot 1-3 I interprete in a way that it is a parent page with child pages but no pictures why on "Include attached files and images" there is no checkbox offered to be checked but on "Include child pages" indeed there is.
In summary: I was able to reproduce your observations on my test instance but from what I now understood this is expected behaviour.
Please let Community know in case of further questions.
I have a similar issue, none of the users on our instance can copy a page. The get the symbol that shows Confluence is processing the command but then after a while we get the same error as you have show above. I have tried different pages in different spaces with the same outcome. I am admin and have ensured create page permissions have been granted. I have resorted to exporting the page to a Microsoft .doc file then converting it to a .docx file and then importing it.
For the error shown above I'd recommend to take a look into log files assuming it is a Confluence server (not cloud) because it differs from the initial effect the user observed.
If it does not help I would further suggest to open a new post here in Community.