I have a system running an Oracle database (12c, 64bit) and I need to have ArcMap running on this same system connect to the database. ArcMap is 32bit so I also have the 32bit Oracle 12c instant client on the system. The user I was connected as when I set all of this up works fine having the 64bit oracle server path first in the environment variables. But any other user on this system gets the "Failed to connect to database ... database client software failed to load..." error. All of the discussions on this topic seem to focus on the environment path which I did in order to get the first user to work. But everything is setup the same for the other users yet it doesn't work for them. Is there anything else that could cause the Oracle client to fail to load? Is there any other logs or checks you can perform to see where the problem is coming from?