I got a problem while restoring SP2010 sub-site from our old SP2010 farm to new farm through a full backup. The subsite on old farm had unique permissions. As well as the lists inside the sub-site were also having unique permissions. Now when we restored the sub-site on a new farm, it broke all the security permissions. Now all lists underneath the sub-site were inheriting the permissions from their parent. When we tried to input the permissions manually, It was not doing anything when we clicked on the button to stop inheriting permissions.
Any Idea, what is the cause of this issue?