FNIS XXL for Users Error(5): Invalid Class

[renferal]

I've been using FNIS for Users v7.6 XXL fine for a few years now on my oldrim LE build, but suddenly today it's just started failing with nothing more than a single line:

ERROR(5): Invalid Class

 

I'm reaching out here in hopes someone can help me determine the issue. Things i've tried:

• Temporarily Disabling Antivirus Software
• Runinng as administrator
• Reinstalling with FNIS Creatures, PCEA2, and FNIS XXL.

Since this program doesn't seem to log out any useful information, I've also downloaded Procmon in an effort to try to find the issue. So far I've managed to filter the response codes so that I know I'm just looking at "GennerateFNISForUsers.exe", but I haven't had any luck sourcing the problem in the list to ERROR5.  The stream of repsonses has multiple NAME NOT FOUND erorrs, and a few FILE LOCKED WITH ONLY READERS, but I'm struggling to find the route of the Invalid Class error code.

Does anyone have any advice to further troubleshoot this issue?

[renferal]

I should note, this seems to just be happening to the XXL version. The regular version runs as intended, but obviously does not account the large amount of animations that XXL does.
 

Is it possible that the XXL executable relies on a function that has become deprecated or no longer exists somehow? Or is it something simpler than that...

Edited April 13, 2025 by renferal

[traison]

1 hour ago, renferal said:

I haven't had any luck sourcing the problem in the list to ERROR5.  The stream of repsonses has multiple NAME NOT FOUND erorrs, and a few FILE LOCKED WITH ONLY READERS

 

Error 0x5 (or sometimes 0xc0000005) is ERROR_ACCESS_DENIED.

 

1 hour ago, renferal said:

I'm struggling to find the route of the Invalid Class error code.

 

Using a strings port for Windows on the FNIS exe reveals that this string is not in GenerateFNISforUsers.exe. Its coming from somewhere else.

 

Edits: and it's not in the English.txt language file either.

 

1 hour ago, renferal said:

I've also downloaded Procmon in an effort to try to find the issue.

 

I used this together with a decompile produced by ILSpy to narrow down the lines of code where it might have bailed out. Procmon on its own will not reveal the source of the problem if the problem is coming from WMI, like it did in this thread. WMI uses "namespace" and "class" in its terminology.

 

So the question is, what is FNIS doing with "temporary_logs\\FNISListCollect.txt" on your end? Open and flush? Does it write bytes to it?

Edited April 13, 2025 by traison

[renferal]

Quote

So the question is, what is FNIS doing with "temporary_logs\\FNISListCollect.txt" on your end? Open and flush? Does it write bytes to it?

Yeah, it's writing bites to it. Looks like it's spitting out the exact message showing in the white log window of the executable.

 

'FNIS Behavior V7.6 XXL   4/13/2025 2:56:45 PM
'Skyrim 32bit: 1.9.32.0 - D:\SteamLibrary\steamapps\common\Skyrim\ (Steam)
'
'Skeleton(hkx) female: XPMS2HDT (115 bones)   male: XPMS2HDT (115 bones)
'Patch: "SKELETON Arm Fix"  
'Patch: * DServant's "Archery Gameplay Overhaul"  (CTD:0.1%)
'
'
ERROR(5): Invalid class 

 

[renferal]

The strange thing to me is that the original non-XXL version operates without this error. I would assume the only major difference between the two would be a variable change to increase the animation load, but I guess something else must be substantially different between the two versions.

I thought it might be a space-allocation issue, as the drive I was putting these on was getting pretty full. But I just cleared up 280 GB of storage for it and still it runs into the ERROR5.
I've also run the gambit on UAC within windows to allow it have as much access as it needs. Even more so than I did with the original file. No luck there. 
 

[traison]

39 minutes ago, renferal said:

Yeah, it's writing bites to it. Looks like it's spitting out the exact message showing in the white log window of the executable.

 

You're looking at "temporary_logs\\GenerateFNIS_LogFile.txt". Wrong file.

[Kastagir]

According to Fore, all error numbers 2000 and below are reported by windows, so the problem is your system, system access, antivirus, UAC or something else on your end - not caused by a mod.  Take a look at this thread where another user encountered the same thing after an update to Windows (probably Windows Defender) and resolved it by rolling back the update.  If that's your issue then you need to make further efforts to create exceptions for GenerateFNISForUsers.exe (or MO if you're using that) in your antivirus tools.

[renferal]

On 4/13/2025 at 3:39 PM, traison said:

 

You're looking at "temporary_logs\\GenerateFNIS_LogFile.txt". Wrong file.

No it's not, the code text I copied is from the one you mentioned. FNISListCollect.txt.
 

 

On 4/13/2025 at 3:53 PM, Kastagir said:

According to Fore, all error numbers 2000 and below are reported by windows, so the problem is your system, system access, antivirus, UAC or something else on your end - not caused by a mod.  Take a look at this thread where another user encountered the same thing after an update to Windows (probably Windows Defender) and resolved it by rolling back the update.  If that's your issue then you need to make further efforts to create exceptions for GenerateFNISForUsers.exe (or MO if you're using that) in your antivirus tools.

Thanks for the thread link. I hadn't seen that one. I've turned off my AV protection for moments at a time while testing this, as well as checking the quarantine box in case a file had been captured by it - but to no luck. 

I think it's probably right to assume that its something a new Windows update did though. My installation isn't on the C:/ drive, so I shouldn't have issues with that. Unless they've extended UAC to other drives like you mentioned...

One thing I haven't tried is adding exceptions to Windows Firewall for this. Or Windows Defender. I'll try doing that and see if those are workarounds

[traison]

1 hour ago, renferal said:

No it's not

 

Ah I see its writing into both files at once from the LogOutput function.

 

1 hour ago, renferal said:

I'll try doing that and see if those are workarounds

 

Don't forget about the WMI fix in the thread in my first post. This still seems like the most likely solution.

[renferal]

Finally got this fixed. You were right, Traison, it was a WMI issue! I was just stubborn and didn't want to run a bat file I found on the internet if I could help it. Call me old-hat.

I did actually find a more user-friendly version, for anyone running into this issue in the future. I followed the guides outlined here in this walkthrough:
https://kb.sambapos.com/en/11-5-how-to-resolve-invalid-class-error/

This is not a walkthrough specifically for FNIS, mind you, just another company who's run into the same problem. Their solution was a bit easier for me than trusting a bat file.
 

I followed Method 2 of that link and it started working again. In case that link gets taken down, the steps are this:

 

1. Enter Windows Start > Services > Services Application > Windows Management Instrumentation service. Stop the service.

2. Navigate to C:\Windows\system32\wbem\. Find the repository folder. Rename that folder to repository_old. (This backs up the folder, and a new one will be generated when you start the service again. You can actually use this method with a lot of files when modding Skyrim, too  )

3. Go back to Services and Start the Windows Management Instrumentation again. This should generate a new repository folder.

That's all it took to get me back up and running again! There's further methods on that link others can try if that doesn't work. The core problem seems to be the same. Invalid Class seems to be indicative of a WMI corruption, or a not running WMI service.

Edited May 5, 2025 by renferal

[Kastagir]

This sounds to me like yet another reason not to use Mod Organizer.  I've never encountered this error and it's my firm belief any modding tool that requires me to stop Windows services and force regeneration of system files indicates that the tool is the problem and the threat, not the operating system.  WMI does a lot of things, and making sure that MO can do its thing is probably in the least important 5% of those.

[renferal]

16 hours ago, Kastagir said:

This sounds to me like yet another reason not to use Mod Organizer.  I've never encountered this error and it's my firm belief any modding tool that requires me to stop Windows services and force regeneration of system files indicates that the tool is the problem and the threat, not the operating system.  WMI does a lot of things, and making sure that MO can do its thing is probably in the least important 5% of those.

I don't think it has anything with MO, because I don't use it. It was probably a windows update that bricked/corrupted the service. The fact that there's another company out there that felt the need to put out a guide on how to rectify the issue speaks to that problem arising in more circles than just modding skyrim.

[Kastagir]

1 hour ago, renferal said:

I don't think it has anything with MO, because I don't use it. It was probably a windows update that bricked/corrupted the service. The fact that there's another company out there that felt the need to put out a guide on how to rectify the issue speaks to that problem arising in more circles than just modding skyrim.

Are you on Windows 11?  FNIS was made in the era of Windows 10 so if Windows 11 is doing things that breaks FNIS (or components used by FNIS) that would be good to know.  It's not as if something like that hasn't happened before...

Edited May 6, 2025 by Kastagir

[renferal]

On 5/6/2025 at 4:41 PM, Kastagir said:

Are you on Windows 11?  FNIS was made in the era of Windows 10 so if Windows 11 is doing things that breaks FNIS (or components used by FNIS) that would be good to know.  It's not as if something like that hasn't happened before...

Nope. Still on 10.