X-Server access is denied on host

The situation is: I have a RHEL 7.3 VM that I am able to access via both ssh and VM console. I am able to run all of the standard commands for verifying that X11 forwarding/xhost permissions are working (xclock, nautilus, firefox, etc.) i can also run the runInstaller for Oracle client, No problems in any of these situations.
However, attempting to run the installation of Oracle WebLogic 12.1.3
with : cissys as user and the ligne command: java -jar fmw_12.1.3.0.0_wls.jar.
try with oracle user = same error.
results in the following :
Launcher log file is /tmp/OraInstall2017-07-25_03-14-27PM/launcher2017-07-25_03-14-27PM.log.
Extracting files.........
Java HotSpot(TM) Client VM warning: You have loaded library /tmp/orcl5779090421142529968.tmp/Disk1/install/linux/libjni.so which might have disabled stack guard. The VM will try to fix the stack guard now.
It's highly recommended that you fix the library with 'execstack -c ', or link it with '-z noexecstack'.
Starting Oracle Universal Installer
Checking if CPU speed is above 300 MHz. Actual 1696.120 MHz Passed
Checking monitor: must be configured to display at least 256 colors. Actual 16777216 Passed
Checking swap space: must be greater than 512 MB. Actual 7815164 MB Passed
Checking if this platform requires a 64-bit JVM. Actual 32 Passed (64-bit not required)
Checking temp space: must be greater than 300 MB. Actual 2956 MB Passed
Preparing to launch the Oracle Universal Installer from /tmp/OraInstall2017-07-25_03-14-27PM
Java HotSpot(TM) Client VM warning: ignoring option MaxPermSize=512m; support was removed in 8.0
Log: /tmp/OraInstall2017-07-25_03-14-27PM/install2017-07-25_03-14-27PM.log
X-Server access is denied on host
[Fatal Error] DISPLAY variable set incorrectly: 172.16.40.30:0.0
[Resolution] Verify that your DISPLAY environment variable is set correctly,
and that there is an X11 server on the system. If you are
running the Oracle Installer as a different user or on a different host,
you may need to use the xhost command to ensure that host/user
has permission to write to your display.
I've tried just about every troubleshooting step that I can think of and every troubleshooting step that Google has provided me.
If anyone has any idea of an obvious or less-than-obvious culprit, I would absolutely love to hear it.