Hello,
I'm a site collection admin so I do not have this issue. However, when end users (whom are site owners) try to save their list as a template, they get the Access Denied page. I've found from my research, the end user does not have the correct permissions to the List template gallery which is at the root. The end users have read only permissions at the root. I've also found that to fix this issue, the end users will need Design permissions at minimum at the root or on the List template gallery. Is all the permissions to include in the Design permission level necessary for this to work? I do not want to give the end users all permissions in the Design group.