Myth 2 crashes (EXCEPTION_PRIV_INSTRUCTION)

[greendestiny]

Hey guys, I appreciate any and all help with this. I'm running WinXP SP3 and until just a while ago, Myth 2 was working perfectly.
Then, when I tried to once more own some Myrkridia with Trows and Dwarven Mortar Heroes, the game won't start at all.
1.0 version just gives me a busy cursor for a few seconds and that's it.
1.6 version gives me a black screen for a few seconds and then drops me to desktop.
1.7 looks like it's going to start, it goes black screen, cursor disappears, but after a bit more than other versions, it also drops me to desktop. I've tried Classic and Windowed versions and it doesn't seem to make a difference.
Myth_log.txt has this to say:

1.6
===
2011-04-12 05:39:04
Myth II Build 290 running under Modern Windows 5.010000 ----------------------------------------------
Scanning for software devices...
Found 1 to use
Scanning for Direct3D devices...
Found 1 to use
Scanning for 3Dfx devices...
Myth Crashed.

1.7
===
2011-04-12 05:45:45
Myth II Classic Build 356 running under Modern Windows 5.010000 ----------------------------------------------
Loading poweruser.txt... not found.
Scanning for software devices...
Found 1 to use
Scanning for Direct3D devices...
Found 1 to use
Scanning for 3Dfx devices...
Myth Crashed (EXCEPTION_PRIV_INSTRUCTION)
Attempting Stack Trace...
0 0x0ebae414 ? + 0x0000 (?:0)
1 0x7c817077 ? + 0x0000 (?:0)
Stack Trace Complete

I'm also using Avira AntiVir and ThreatFire. Avira has shown some hyper-aggressive behavior, but neither of these programs' Status or Event logs show anything about blocking Myth II.exe

dxdiag shows nothing out of the ordinary, except that smwdm.sys isn't digitally signed.

If you need more data, just let me know. If I can't make Myth 2 work properly again, I'll just copy my favorite saves and recordings to a safe place and wait for a better time, I guess. And I will always have TFL and Shadow of the Mountain +_+

[Pyro]

Is your plugins folder empty? I am wondering why the patch plugins aren't appearing in the log at all. Have you tried 1.7.1? Do you have more than one Myth 2 folder? Maybe you are trying on an incomplete one. Check inside your Myth II folder for the "tags" folder and make sure there are files in there.

[greendestiny]

Is your plugins folder empty? I am wondering why the patch plugins aren't appearing in the log at all. Have you tried 1.7.1? Do you have more than one Myth 2 folder? Maybe you are trying on an incomplete one. Check inside your Myth II folder for the "tags" folder and make sure there are files in there.

You're on to something, because I used Windows System Restore, was unhappy with the results and tried to undo it and got "Undo failed". That's the most significant event that happened since I last played Myth 2.
Plugin folder contains:
- Patch 1.2
- Patch 1.3
- Patch 1.4
- Patch 1.4 Interface
- Patch 1.5
- Patch 1.5 Unity
- Patch 1.7 Templates

Tags folder has files in it (around 500 MB in size).

I have only one Myth 2 folder.
I got both 1.6 and 1.7 from projectmagma.net.
Previously I had Myth 2 in My Documents folder and it worked fine. But still, I've tried uninstalling and installing to Program Files folder, right on the C disc and so on and the exact same errors occur.

I had a bunch of plugins (Chimaera, Fallen Levels, etc), but I removed them because then Myth log would show "error found in monolithic tag file".

I want to mention that I have Myth 3 installed as well and it's working ok. Maybe Myth 3 causes all these problems? Should I try uninstalling it?

[Pyro]

Myth 3 won't affect Myth 2. Do you have your latest graphics card drivers installed? Download 1.7.1 and install that update and see if that works. Had any viruses on that computer? If so, it is possible it corrupted your Myth executables which could explain your strange crash. So download 1.7.1 found at the Tain and install it.

A virus could even explain why you get errors with your plugins. But first check with 1.7.1 and tell us how it goes.

[Myrd]

The plugins aren't appearing because Myth crashes before it gets to that point.

From the logs, it looks like it's crashing trying to detect 3Dfx hardware.

What graphics card are you actually using and do you have the updated drivers for it?

[greendestiny]

I'm using Radeon 9250.
As concerning drivers for it, I used to have graphical glitches in games until I installed a graphics driver pack. After that all other games functioned properly. Still, I don't think there's the cause.
I'm pretty aware of malware activity and I've done full scans, with nothing found.
I think I have best freeware AV protection possible.
I will try uninstalling my antivirus programs and see if that helps.

[punkUser]

What do you mean by "driver pack"? Did you install the official drivers from ATI/AMD or something else?

[Myrd]

I don't think 3Dfx is supposed to be supported on your card.

I'm guessing whatever "driver pack" you installed added some kind of 3Dfx emulation layer that doesn't work well with Myth (e.g. something like: http://www.svenswrapper.de/english/index.html).

[Melekor]

That would be my guess as well. Try searching your computer for glide2x.dll, if you find it, try renaming it to glide2x.dll.bak, then see if Myth runs. That would confirm the 3Dfx theory.

If that is correct, you probably want to uninstall the driver pack and install the official drivers for your 9250.
They can be found here:
http://support.amd.com/us/gpudownload/Pages/index.aspx