Access denied while accessing Site Permission under a subsite

Question

User with full control over root site/subsite, gets Access Denied error while trying to access Site permissions under Site Settings of a specific subsite. Same user is able to access Site permissions of all other subsite including the root site.

1. User has access to the MP gallery/Style Library.
2. All MPs and CSS are checked-in/published.
3. User has Full Control on the subsite. Given explicitly.
4. The site uses the same MP (across entire site collection).

Everything seems to be correct but unable to figure out what can go wrong only with one subsite. Kindly help.

Answer 1

Make sure that

• The subsite hasn't been broken inheritance and not have a custom permission ,
• Try to login to this SubSite using Site collection administrator to make sure that the issue is related to site permission and this user, not a general user.
  • if it's related to this user try to assign it to this subsite at Users and groups using Site Collection administrator or farm account.

Answer 2

The solution that worked for me was restoring site owner access to the hidden Access Requests list. I do not know how permissions were lost in the first place. While on the Access requests and invitations page I opened Developer Tool to obtain the list GUID. I then entered the list GUID into the address bar and re-granted access to the site's Owners group. Step-by-step instructions with screenshots are available at https://jennyssharepointtips.wordpress.com/2017/11/08/restore-lost-permissions-to-access-requests-and-invitations-and-or-site-permissions/.