If I am not wrong this is the issue:
If you login as administrator then it's working fine else getting connection issue right?
Step 1: Create a user group (UDT_Users) in CMC
Step 2: Add users to this group
Step 3: Go to application in CMC > Information Design Tool > User Security > Provide access to user group (UDT_Users) with rights as shown in screenshot.
Step 4: Now ask users to login. atleast it should allow to go in then you can check for universe security.
else just assign these users to 'Universe Designer Users (User Group)' if this group is still valid, this is the group comes by default.