Lua error in Ubuntu

[WilliamRiddle]

Fresh today install of Ubuntu, all updated, tried to run the tutorial and got this error right out of the box:

[5/8/2026 4:39:31 PM] [ERROR] LOADTHREAD: System.DllNotFoundException: lua5.1 assembly:<unknown assembly> type:<unknown type> member: (null)

Please advise.

Thanks in advance!
wr

[Moon Wizard]

I noticed some missing files in the commit earlier today; and pushed a new build about 4 hours ago. Can you please run a new Check for Updates, and let us know if still an issue?
(May need re-install if can't start client at all.)

Regards,
JPG

[WilliamRiddle]

I noticed some missing files in the commit earlier today; and pushed a new build about 4 hours ago. Can you please run a new Check for Updates, and let us know if still an issue?
(May need re-install if can't start client at all.)

Regards,
JPG

Sorry for the late response, was away this weekend.

Still getting an error:
[5/11/2026 8:23:27 AM] [ERROR] LOADTHREAD: System.DllNotFoundException: lua5.1 assembly:<unknown assembly> type:<unknown type> member: (null)


wr

[WilliamRiddle]

Sorry ... forgot to ask.

uninstall/reinstall ... not sure how to do that on Linux with FG. It'll take longer, but I can just reinstalled the entire Ubuntu OS if you think that would be needed. I had only just done the OS install, then moved right to FG.

Or ... if there is a way to drop a file into a directory?

Funny thing is, I have another (older) laptop with Zorin installed I built a few weeks ago and it works like a charm. This (current) laptop is an old Windows 10 Dell for a friend and they asked for Ubuntu, as that is what the FG wiki says is the default for FG.

Thanks in advance,
wr

[Moon Wizard]

I'm not getting any other reports from Linux users; including superteddy57 on our team who uses Linux. So, not sure why that is happening.

Do you have any security software that may be blocking? Can you try an uninstall/reinstall?

Regards,
JPG

[ju95]

Sorry ... forgot to ask.

uninstall/reinstall ... not sure how to do that on Linux with FG. It'll take longer, but I can just reinstalled the entire Ubuntu OS if you think that would be needed. I had only just done the OS install, then moved right to FG.

Or ... if there is a way to drop a file into a directory?

Funny thing is, I have another (older) laptop with Zorin installed I built a few weeks ago and it works like a charm. This (current) laptop is an old Windows 10 Dell for a friend and they asked for Ubuntu, as that is what the FG wiki says is the default for FG.

Thanks in advance,
wr

To clarify, are you trying to use the old Windows 10 Fantasy Grounds application on Ubuntu from their storage, or did you download the linux installer from the site or steam?

[Speculi]

uninstall/reinstall ... not sure how to do that on Linux with FG.
https://fantasygroundsunity.atlassian.net/wiki/spaces/FGCP/pages/1978138625/Uninstalling+Fantasy+Grounds+VTT#Uninstall-Fantasy-Grounds-VTT-in-Ubuntu-Linux
https://fantasygroundsunity.atlassian.net/wiki/spaces/FGCP/pages/1920532481/Manually+Uninstall+Fantasy+Grounds+VTT#Manual-Uninstall---Linux

[WilliamRiddle]

To clarify, are you trying to use the old Windows 10 Fantasy Grounds application on Ubuntu from their storage, or did you download the linux installer from the site or steam?

No. This is an old Dell Windows 10 laptop workstation that has been reformatted for Ubuntu. A wiped disk and clean install build of only Ubuntu desktop 26.04. After install ran all of the Ubuntu updates, then downloaded the FG Linux installer and followed the instructions on the FG wiki. No other mods or app installs outside of the Ubuntu defaults. Then logged in with my account and updated. After done cannot load Campaigns, generates the reported error.

I should have an update on another wipe and reinstall tomorrow.

wr

[shindaseishin]

I'm getting the same error. I am in the process of prepping an old laptop to take with me on a trip and I'm installing FGU so that I won't miss my group's session while I'm away. I downloaded the Linux installer and ran it. I get the same error as in the first post in this thread. It happens if I try to load a local campaign (I tried both the default tutorial 5e campaign and a fresh Traveller campaign), connect to a LAN server, or connect to a public server. As soon as it finishes loading the files it crashes back out to the loader and displays that message.

This is not happening to the copy on my main desktop computer.

The desktop is using Ubuntu 26.04 and the laptop is using Fedora 44.

[Moon Wizard]

Just tried something else. Can you try a new run of the updater to Check for Updates again?

Regards,
JPG

[shindaseishin]

Whatever you did, Moon Wizard, it now works for me. Thanks.

[WilliamRiddle]

Just tried something else. Can you try a new run of the updater to Check for Updates again?

Regards,
JPG

Hey all, I think I have some more info on this.

Short backstory ... I work in IT and we get a lot of 5+ year old laptops from remote staff back for upgrades. Occasionally some are in decent shape so we give them to employees/friends/family, but since we don't want our corporate copy of Windows on them we typically dump a Linux distro on to wipe them.

Recently one of our engineers retired and I ended up with a Dell Precisions M6800 workstation laptop BEAST which was top of the line 10 years ago. The thing still screams, but cannot run Windows 11. Not wanting to waste an i7, 1GB HD, Nividia (or AMD, not sure yet) card, and 32gigs of RAM I thought why not turn it into a backup FG box for home. Everything was fine ... until I got that error and posted this thread.

After replies from Moon, I did a complete reload ... nothing. I also tried an install of Zorin, which I've used before on newer (3-4 years old) HP laptops and they work great with FG. Still got the same error. Then shindaseishin posted he is seeing the same error with an older system. That made me think that maybe we have a weird legacy hardware issue going on.

This morning I took a 3-year old Dell Inspiron 3511 that just came back in and loaded Ubuntu and FG. This was a Windows 11 HOME laptop. It works great, which is why I think we might have a weird hardware issue.

Right off the top of my head, the only thing I know for sure about this Dell M6800 (other than it weights nearly 15lbs) is that it does not have the newer Win11 TPM chip. Not sure if that matters to FG or not. After that, the older graphics card maybe? Some other older hardware not compatible with Unity SM might know about? These units also came with either Nvidia or AMD cards. I don't know which at the moment, I'll have to pop the cover if I can't figure out how to tell from the install. Funny thing is, I've had older laptops than this run FG up until maybe the past six months (finally retired it), so not sure what else might have changed.

I'll run another check update on the M6800 (it's been nearly two days) and see if it responds. Right now it has Zorin on it.

wr

[LordEntrails]

I used to lug one of those M6800s around. "Mobile" workstation was... almost false advertising ;)

[WilliamRiddle]

Whatever you did, Moon Wizard, it now works for me. Thanks.

Ditto. That worked here too. :)

wr