Hi Johnny,
To troubleshoot this issue, please share with us more details about it:
- Can you copy and paste this workbook normally after you change its’ file extension name? Can you copy and paste them normally if you create one new workbook that with the same pictures?
- Does this issue happen to all workbooks or just this one or some workbooks with the same file extension name?
- Does Word have the same issue?
- What have you changed before this issue happens? (E.g. Update OS/Office)
- The version number of your OS(Win+R>type CMD) and your Office(File>Account>Product Information)
Besides, you can send us your workbook via Private Message.
Thanks,
NeoWu