[dk0]

Ok, I'm glad you posted this, because I've been troubleshooting the exact same issue without really getting anywhere. It's recently gotten me killed a couple times because I have no other choice but to /ex and come back. I haven't tried going full screen and coming back, but I'll do that next time.

Question: are you using Nvidia video card?

If you check Windows Event Viewer, this video lockup always throws an error:

4101 Display driver nvlddmkm stopped responding and has successfully recovered.

Searching this led me to the common problem related to the Timeout Detection and Recovery (TDR) feature of your graphics card. I've increased these settings in my registry from defaults (5 and 2 seconds, respectively) to 60 seconds each. It may have helped a bit, but the hangs still happen:

HKEY_LOCAL_MACHINE
    SYSTEM
        CurrentControlSet
            Control
                GraphicsDrivers
                    TdrDdiDelay=60
                    TdrDelay=60

I've also used DDU (Display Driver Uninstaller) to completely clear out any artifacts related to graphics drivers. I also used to the tool to prevent Windows from automatically trying to update or change graphics drivers. Then I manually installed the latest from Nvidia.

I still get hangs.

To others saying it's related to applications asking for elevated permissions: this is 100% not true, at least for me. It appears to be the case because when Windows UAC kicks in, the fullscreen video overlay flashes on screen to ask for confirmation-- it's this fullscreen overlay that causes p99 to lockup. Change Windows so that UAC doesn't include the fullscreen overlay and this won't be a problem anymore. EQ will also lockup if you try to launch another fullscreen game while EQ is open -- it's always graphics related.

I've been playing p99 for years on an Nvidia card with no issues. I've been on my current machine since April with no issues until the last few months. Nothing has really changed on my machine over that time, except for Windows updates.

As such, I believe it's either
A) an nvidia graphics driver update sometime around September-October suddenly broke this

or

B) the p99 graphics update related to vision/dynamic lighting is leading to a conflict that's causing the lockup


I'll roll back to earlier drivers hopefully today and see if I make any progress. I'm open to any other input or ideas from other users who might have more experience here.