Try to reboot the server if that does not work follow the below mentioned steps
1. Right-click on %SystemRoot%\System32\winevt\logs and select Properties.
2. Select the Security tab.
3. Click Edit button and click the Add button in the permissions dialog box.
4. In Select users, computers, or Groups dialog box ensure that under object types Built in Security Principals and the location as local computer name is selected.
5. Enter the object name as “NT SERVICE\EventLog” without quotes. And click OK. This group should have full control on the folder.
6. Once EventLog group is added add the rest of the groups with above mentioned permissions.