Steps to Reproduce
Add a read ACL to the sys_attachment table.
Log in with a user that does not meet the read ACL but can view the Sys Updates table.
Type sys_update.list in the filter navigator to access the Sys Updates table.
The system shows the list of update records.
Right-click the list headers and select Export > Excel.
The system displays a blank page.
Do not create a read ACL to the sys_attachment table.
Related Problem: PRB712842