I have solved my "ntdll.dll" errors on both my home server, Gladden, and the test server, Bullroarer. I am posting this here to try to help everyone else who is getting the same Lotroclient failure error.
I am running Windows XP 32-bit on an Asus P6T Deluxe motherboard that has 6G of memory and an Analog Devices SoundMaxx audio chip on it. SoundMaxx is the keyword here!
I don't run other programs while I am gaming because Lotro is a memory pig and is a very large, all consuming memory pig on 32-bit OS's. There is NO ROOM for your favorite music blaster when you're riding around Rohan, so please don't run the program or, if you do, don't complain about it here!. Get rid of your other favorite memory sucking programs too, while you're at it ...
There is an excellent post about Lotro and 32-bit OS memory allocation issues in this forum by Chromite Swiftpaw. You can find it here: https://www.lotro.com/forums/showthr...32-bit-Windows
I found three things that caused Lotroclient to fail with the "ntdll.dll" error. These are the issues I found and the order in which I repaired them.
1. The nvidia drivers for my evga 285 GTX were not up to date so I fixed that. The SoundMaxx drivers on the Asus website were up to date except for the "BETA" version (BETA in red letters) so I left those alone ... big mistake!
Got fewer "ntdll.dll" errors after I upgraded my graphics driver but the problem was still there.
2. Checked for Unknown System Devices (the grey, diamond-shaped icon at the bottom of the devices list) in Device Manager and found three CT***.sys files left over from a Soundblaster card install I had done way back when. After checking their Properties, I used Device Manager to Disable and Uninstall all three CT***.sys drivers ... never, ever buy a Creative Labs sound card; the hardware and software quality has gone to hell in a handbasket ever since the Vista drivers release and their tech support has become non-existent.
Got even fewer "ntdll.dll" errors after cleaning out all the unused Unknown System Devices but the problem was still there; especially on Bullroarer!
3. Went back to the Asus website to get the BETA SoundMaxx driver (BETA in red letters for "use at your own risk") dated back to 2010. Why something stayed in BETA state for three years is beyond me. Must be something Asus ... as in we can't admit we made a mistake but we can publish a BETA driver to fix it ... effing idiots! Downloaded and installed the BETA SoundMaxx drivers. Cringed while I did it because I dislike using BETA system drivers as they have been known to introduce more unwanted, rather than fix, problems.
Lotroclient failure problems with "ntdll.dll" errors went away. Played for two plus hours on Gladden and another hour on Bullroarer without one "ntdll.dll" error. I used a character on Bullroarer that I could not move ten meters or zone or fight for 10 minutes without getting an "ntdll.dll" error. No errors there either.
My point is the Tech Support guys are right when they tell you that the "ntdll.dll" errors are most likely caused by some Superb Hierarchically Integrated Technology driver program Lotro uses to run the game on your computer. So go to your motherboard or PC vendor's website to verify you are running their latest drivers.
Sometimes going to one vendor's website is not enough so you may have to go to a chipset manufacturer's website to get their latest drivers, as in going to nvidia.com or amd.com to get their latest graphics driver.
If you find that a newer BIOS exists for your computer, try to find out what it fixes before you download and install it. I have bricked a few of my PCs by screwing up a BIOS upgrade; e.g. always save a copy of the old BIOS before you install the newer one, always read the instructions twice before you start any upgrade of anything. Vendors leave things out of their BIOS upgrade descriptions; especially the fixes that correct their embarassing mistakes.
It's too bad we don't have a list of these solutions on the forums anywhere; a moderated list by motherboard solution would have made my life a lot easier.
Hope this helps ...