1. Login to liferay.
2. Create 2 organizations.
3. Make one the child of the other.
4. In the child organization, create a new user and assign them the Organization Admin role.
5. Sign in as the user from step 4.
6. Go to Control Panel-> Users and Organizations.
7. Under "Search All Organizations" click on the organization
7. Click on the "Back to (parent organization)" link
Tomcat should populate the error log from the customers attached document. I was able to replicate the exact error in my tomcat.
I suspect that this is a permissions issue and is working as intended, because the link redirects the user to an organization they lack admin privileges to.