On 27JUL17, we updated the 737, 747 and 777 product lines with a small protection against an unusual failure mode that is present only in Prepar3D v3.1 and later through v4.x.
We have added a protection that requires users to "Opt In" to activating the captains PFD as a Pop-Up display. You can access this in the Options menu in order to turn the protection OFF/ON as suits your needs. Most users will be able to activate this feature without trouble, but we are requiring users to opt-in in order to bring attention to an easily preventable
CTD problem some users may not be aware can be avoided.
BACKGROUND YOU NEED TO KNOW:
When Lockheed Martin released Prepar3D v3.1, something changed deep in the internals of Prepar3D that induces a CTD for **some** users under a very specific set of circumstances. The CTD would occur 3-8hrs (actual time, not sim-time) into a flight if the user made any use of the Captain's PFD as a "pop up" display by clicking on the left PFD. We have been seeking Lockheed Martin's attention to this issue for more than a year, but the issue is so difficult to reproduce, neither Lockheed Martin nor PMDG have succeeded in finding an in-house reproduction case that is consistent enough to allow debugging.
HOW DO I KNOW WHAT SETTING TO CHOOSE?:
We defaulted this setting to disallow use of the Captain's PFD as a pop-up display, even though 99% of users did not experience the CTD. We selected it to OFF in order to force awareness of the issue by making users manually select the setting to ON. When you select ON, you will get a small warning window to bring to your attention the fact that if you have a CTD sometime in the 3-9hrs range, you may want to consider selecting this item back OFF.
We hope that this will help users avoid a problem we have been unable to convince Lockheed Martin to fix...