In 1.7.x context is id=1 contectlevel=10 instanceid=1 and all work correctly. But after upgrade moodle not found this context and create new:
id=xxx contectlevel=10 instanceid=0.
As the rights of the administrator are appointed in an old context, the administrator cannot open page of additional parameters at updating at all. After updating the manager has no rights in system.
If manually to remove a new context, and old to correct on id=1 contectlevel=10 instanceid=0, all works correctly.