In order for the 4D for OCI plug-in to function properly, you first need to install the files (libraries) needed to run the Oracle Call Interface (OCI). 
 
    
    
    In just a few simple steps, you can download the Oracle Instant Client and install it.
  - Download the appropriate instantclient-basic-[...] package for your platform here: http://www.oracle.com/technetwork/database/features/instant-client/index-097480.html
Notes: For 4D for OCI, download instantclient-basic-windows.x64-11.1.0.4.0.zip.  - Unzip the packages into a single directory (e.g., C:\oracle\) and rename the subfolder as "instantclient" to get a path such as: C:\oracle\instantclient
  - In the environment variables:
  - Add the ORACLE_HOME variable and set it to the path defined in step 2 (e.g.: C:\oracle\instantclient)
  - Edit the PATH variable and add this same path at the beginning
  
   - Add a "network" subfolder to this path with an "admin" subfolder (e.g.: C:\oracle\instantclient\network\admin)
  - In this "admin" subfolder, create a "tnsnames.ora" file with the parameters to your Oracle server. 
For example:
XE =
  (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.10.10)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = XE)
    )
  )