This error is usually caused by DEP (Data Execution Prevention).  Typically you can follow the suggestions to fix in this using the following article.

But if the problem continues to persist after changing these settings and rebooting the computer, then you will need to turn DEP off completely for the computer system as a whole.

To Do So:

Close ALL open computer applications.

Open the command prompt.

Type: bcdedit /set {current} nx AlwaysOff

Hit Enter

NOTE: There are spaces after:

bcdedit

/set

{current}

and nx

Use {Current} or the name of plex in place of Current

AlwaysOff IS case sensitive.

Once the operation says complete you will need to restart the computer for the change to take affect.