PZ ManualThe client and the running server need matching Workshop content. Ask the server operator to stop and update the server, let Steam finish the client’s downloads, then restart and retry. Matching the Workshop item ID alone does not prove that both sides loaded the same revision. If you only join someone else’s server, you cannot repair its copy from your PC.
Separate three different mismatches
Write down the exact message and Workshop ID if one is shown. A “Host must allow you to join” message is an invitation issue; it needs a different check. Do not spend time increasing RAM for a content-version message.
| What differs | What to check | Who can change it |
|---|---|---|
| Game patch or branch | Full version in client and server startup output, including Stable/Unstable | Each installation owner |
| Workshop revision | The item named in the error, update/download state and server startup logs | Client owner and server operator |
| Mod configuration or dependencies | Author’s supported game build, required items and enabled mod IDs | Server operator and clients as required by that mod |
Source: The Indie Stone · 42.20 mod-version handling report · Build 42 community problem report
If you are joining someone else’s server
- Close Project Zomboid and inspect Steam Downloads. Allow the relevant Workshop download to finish; a queued or paused update is not installed content.
- Ask the operator whether the server has restarted since the mod author’s latest update. Send the exact item ID/error, your complete patch and the time of the failed join.
- After the operator confirms the server update and a successful start, launch the client again and join the same address/profile. Record whether the original error disappears or is replaced by a different failure.
- If every player fails, prioritize the server’s loaded copy and collection. If only you fail while another player joins with the same setup, inspect your local download and enabled dependencies. This comparison narrows the investigation; it does not prove a cause.
Source: The Indie Stone · connecting to a server with outdated mods · Support administrator clarification · 2024
If you operate the Host or dedicated server
- Tell the group to disconnect. Save and stop the server cleanly using your normal administration workflow. Back up its complete data and profile before recovery changes.
- Record the active profile, full game build, Workshop item IDs and author-required dependencies. A numeric Workshop ID and a mod’s internal ID are different fields; do not replace one with the other.
- Run the normal update/start workflow for that installation. Wait for Workshop downloads and a successful server-start message, inspecting the first relevant failure rather than repeatedly launching a broken process.
- Have one player with completed Steam downloads retry before inviting the full group. Preserve both client and server output if the mismatch remains.
- Use a separate disposable profile to test the smallest failing mod set and its dependencies. Do not remove mods from the only existing world to create this comparison.
Source: The Indie Stone · force-update Workshop items on a local host · Historical support response · Build 41.60
When a targeted re-download is justified
Use this only after identifying the affected item and checking that the update actually completed. Historical support recommends refreshing server Workshop content when the cached copy is stale. Locate the Workshop cache belonging to the server installation, not a similarly named folder in the world-save directory. Record the path and preserve a copy before replacing identified cached content.
On the client, Steam subscription/re-download controls may refresh the affected item. Some mods also install files outside Workshop; follow that author’s cleanup instructions. Removing a subscription does not necessarily undo a custom loader. Refresh the specific item and its dependencies, then recheck logs; deleting every mod or the Zomboid data folder is not a useful first step.
Source: The Indie Stone · force-update Workshop items on a local host · Historical support response · Build 41.60
Know what the download indicator proves
Valve’s Workshop documentation distinguishes an item needing an update, a download in progress and usable installed content. The practical check is completion plus a successful game/server load. This website does not provide Steamworks API calls as player commands.
If an author removes an item, changes its supported branch or ships a faulty revision, a fresh download cannot manufacture a compatible copy. Use the author’s supported release or an agreed, separately backed-up test setup. Avoid unknown “fix DLLs” and random file swaps.
Source: Valve · Steam Workshop implementation guide · Official platform documentation
Success checks and the next failure
For support, include patch/branch, Host versus dedicated, operating system, affected item IDs, dependencies, update/restart steps and the exact result. Remove passwords, account secrets and private addresses from any public report.
| Observation | Meaning / next action |
|---|---|
| Original mismatch disappears and expected world loads | Have the group verify joining, mod behavior and persistence through a normal restart. |
| Missing dependency or incompatible-mod error replaces it | Read that mod’s author requirements; the new error needs a separate fix. |
| Mismatch persists after completed downloads | Compare loaded revisions/configuration and collect both logs; ask the operator or author for a supported recovery. |
| Connection timeout replaces it | Investigate address, ports and host network using the dedicated-server guide. |
Choose the next branch
Sources & verification
Original checking steps are editorial recommendations. This site has not run a game test or inspected a local 42.21 installation. Source review and page update dates describe different work.
- The Indie Stone · 42.20 mod-version handling reportRead 8 October 2026. Supports separating a newer client download from a running server’s older copy. A report is not proof of the cause or an unresolved defect in every later patch.
- The Indie Stone · connecting to a server with outdated modsRead 8 October 2026. Beard explains Workshop updates on server restart and the difference from manually installed local mods. This is older support evidence, not a 42.21 reproduction.
- The Indie Stone · force-update Workshop items on a local hostRead 8 October 2026. Beard’s December 2021 responses distinguish server Workshop downloads from the client. Targeted cached-content refresh is a recovery option, not permission to delete world data.
- Valve · Steam Workshop implementation guideRead 8 October 2026. Item installation/update state and completion callbacks explain why starting a download is not proof that usable content is installed. This is an API reference, not a PZ player command.