Frequently asked questions

FAQ

Assistant not showing up?

You are likely on an older linux distro, you will need to either build TazUO from source, or upgrade to a newer distro.

You must install .NET 10+

You will need to install dotnet from Microsoft over here

Editing settings.json

You will need to edit settings.json located in TazUO/settings.json. We recommend using a json editor like https://jsoneditoronline.org to avoid accidentally messing the formatting up.

The main settings you need to change are highlighted in yellow:

ℹ️ The ip and port are from the server you want to play on.
ℹ️ ultimaonlinedirectory is where you have the original ultima online installed at. TUO still needs this to run.

”It’s telling me my UO directory is invalid”

Make sure you either copied your settings.json and /data/ folder over to the new directory or you have edited your settings.json with the correct information.

A config or database file got corrupted — did I lose my settings?

TazUO recovers from corrupt data files instead of crashing:

• A corrupt JSON file (settings.json, a profile, etc.) is backed up to a .corrupt copy next to the original and default settings are used instead; you’re notified in-game which file was affected. Check the .corrupt file if you want to try to recover anything from it manually.
• A corrupt SQLite database is quarantined and an empty database is recreated automatically instead of blocking login.
• If a database file is stuck read-only (common with OneDrive/cloud-sync, antivirus, or restoring the Data folder from a backup), the read-only flag is cleared automatically before opening it.

”Bad uop file” error

A .uop data file is corrupt, truncated, or was interrupted mid-patch. Reinstall or restore the game data files (or re-patch) so the affected .uop file is complete.

Missing TazUO assembly on startup

If the client fails to start because the TazUO assembly is missing, the install/copy is incomplete — re-run the installer or re-copy the client files so TazUO (and its dependencies) are present next to the executable.

”A plugin crashed TazUO while injecting a network packet”

If the crash message mentions a plugin crashing the client during packet injection (e.g. an assistant’s SendToClient handing over a packet that doesn’t fit its buffer), the crash is usually a plugin bug, not a TazUO one:

1. Update the plugin (and any scripting add-ons) to the latest version.
2. Temporarily disable the plugin to confirm it’s the cause.
3. Make sure the plugin points at the same UO data directory TazUO uses.
4. If it keeps happening, report the crash log to the plugin’s author.