Error System.Data.OracleClient requires Oracle client software version 8.1.7 or greater when installs setup
It is a security issue, so to fix it simply do the following:
- Go to the Oracle Client folder.
- Right Click on the folder.
- On security Tab, Add "Authenticated Users" and give this account Read & Execute permission.
- Apply this security for all folders, Subfolders and Files (IMPORTANT).
- Don't Forget to REBOOT your Machine; if you forgot to do this you will still face the same problem unless you restart your machine.
The error message is pretty self-explanatory: your application needs the Oracle Client installed on the machine it's running on. Your development PC already has it. Make sure your target PC has it, too.
Edit: The System.Data.OracleClient namespace is deprecated. Make sure you use the driver native to your database system, that would be ODP.NET from Oracle.
Install Nuget for Oracle.ManagedDataAccess
Make sure you are using header for Oracle:
using Oracle.ManagedDataAccess.Client;
This Worked for me.