Sometime a reboot is required before the Oracle Client install is picked up.
The reboot of the server seems to have rectified the original error but now we get another error
An error occurred when trying to validate the license for this product.
License validation failed. The license agreement installed for this system is for a different version of the software.
So not sure if this is a problem with the license key sent to us or is it to do with he version of Oracle we installed which was 64bit Oracle 12c
I have a couple of troubleshooting questions:
Is it possible to access Service Desk using the Console on the Web Server?
Does the connection to database test ok for Web Access in the Configuration Center?
Thanks for all your help. We have managed to fix the problem.
We rolled back all of our servers and database and ensured that Oracle client was installed on all of the servers and then ran through the upgrade and everything worked fine. So the issue seemed to be that we stupidly uninstalled Oracle from our web servers to free up space and then did the upgrade and installing Oracle client after this didn't fix the problem so couldn't connect to the database again.
So the moral of the story don't try and free up space on your server by uninstalling Oracle DOH!