As of October 23, 2026, with Hytale on 0.7.3 (Update 7, «Chapter I»), the main reason mods fail is the version: Update 7 changed the plugin API and every content mod needs its 0.7 file, so many Update 6 mods no longer work. Next up: the client and server aren’t on the same version, the mod isn’t enabled in that world, or it was installed in the wrong folder. The client logs (%APPDATA%\Hytale\UserData\Logs) and each world’s server logs tell you which mod is failing; if they don’t, remove mods in halves.
Quick diagnosis
| Symptom | Likely cause | What to do |
|---|---|---|
| The world won’t load or crashes after updating to 0.7 | Update 6 mods or plugins | Use their 0.7 file on CurseForge or remove them |
| «Server failed to boot» | The server didn’t start: often an incompatible mod or plugin | Check the server log and remove mods |
| «Failed to connect to server» | Different version between client and server, different branch (patchline) or server down | Update both to the same version |
| The Mod Browser’s Install button is grayed out | The author doesn’t allow downloading it from inside the game | Download it from CurseForge |
| The dedicated server exits with code 11 | It would write its data inside the launcher folder | Install it in its own folder |
| Broken builds after removing a mod | The mod added blocks or items you were using | Restore the world backup |
Step 1: check the versions
Update 7 came out on October 12, 2026 (0.7.0), and since then patches 0.7.1, 0.7.2 and 0.7.3 (October 21) have arrived. The changes that affect mods the most:
- Server plugins: Update 7 removed or changed a large part of the chunk API (for example, ChunkAccessor.performBlockUpdate and WorldChunk.setTicking are gone). An Update 6 plugin needs a new version; you can’t fix it yourself.
- Content mods: every mod that adds blocks, items or creatures must have its 0.7 file. On CurseForge, look in the Files tab for one marked for 0.7; if there isn’t one, remove it until the author updates it.
- Client and server: the official server manual requires them to have exactly the same protocol version. Also make sure your launcher and the server are on the same branch (release or pre-release).
Step 2: read the logs
Official Hytale support lists these folders on Windows (on macOS they’re in ~/Library/Application Support/Hytale and on Linux in ~/.local/share/Hytale):
- Client: %APPDATA%\Hytale\UserData\Logs, with files named [date]_[time]_client.log. It only keeps the 10 most recent: copy yours right away.
- Each world’s server: %APPDATA%\Hytale\UserData\Saves\[world]\logs ([date]_[time]_server.log). A single-player world also runs as a local server, so mod errors when loading a world show up here.
- Launcher: %APPDATA%\Hytale\hytale-launcher.log.
The launcher’s User Data button opens the right folder. Look for the mod’s or .jar’s name near the errors. Since 0.7.3, server owners can also send errors to their own Sentry project with the SentryDsn key in config.json, which includes failures when loading third-party plugins.
Step 3: installation and activation
All Hytale modding runs on the server: anyone joining a modded server doesn’t have to install anything. For your own worlds, mods and packs go in %APPDATA%\Hytale\UserData\Mods and are enabled in the world options when you create it. On a dedicated server, copy them into its mods/ folder with the server shut down, without unzipping the .jar or .zip. If a mod doesn’t show up, check that it’s in the right folder and enabled in that world. Always download from the author’s official page: a .jar runs code on your machine.
Step 4: isolate the culprit mod
- Back up the world (and, on a server, the worlds folder and the config).
- Move half of the mods out of the Mods folder (or the server’s mods/) into another folder.
- Open the world or start the server. If it works, the culprit is in the half you moved out; if not, it’s in the half you left.
- Repeat with the suspect half until you’re down to a single mod.
Test in a new world when you can: according to the 0.7 update guides, removing a mod that adds blocks or items can ruin saved builds that use them. If your Spanish translation mod is acting up, you no longer need it: Spanish has been official since Update 7.
If nothing works
Check that the game runs without any mods in a new world. If it still fails, it’s not a mod: send a report from the launcher (settings cog, bug icon at the bottom right) with the option to attach logs turned on. The launcher sends its log, your last two client or editor logs and the last two server logs.
More Hytale guides: the 0.7 patch and which mods it breaks, server plugins, errors connecting to a server and how to make mods.
Frequently asked questions
Why did my Hytale mods stop working with Update 7?
Because 0.7 changed the plugin API and the game’s content. Every mod needs its 0.7 version; if its CurseForge page doesn’t have one, remove it until it comes out.
Where are the Hytale logs?
Client logs are in %APPDATA%\Hytale\UserData\Logs; server logs are in each world’s logs folder, inside UserData\Saves. The launcher’s User Data button takes you there.
What does «Server failed to boot» mean?
That the server, or your local world, never managed to start. With mods, the most common cause is one that’s incompatible with your version: remove them and add them back one at a time.
Why can’t I install a mod from the Mod Browser?
Since 0.7.1, the Install button is grayed out when the author doesn’t allow downloading from inside the game. Download it from its CurseForge page.
Can removing a mod break my world?
Yes, if it added blocks or items you use in your builds. Back up the world before removing it.