Common issues and fixes. If you don’t see your problem here, DM the admin with a screenshot of the exact error, your Minecraft username, and what step you got stuck on.
You’re on an older Windows build. Install App Installer from the Microsoft Store, which includes winget.
Java still says version 8 after install
Restart your PC — Windows sometimes doesn’t pick up the new PATH until reboot.
Game thrashes / crashes on a low-RAM PC
The instance ships pinned to an 8 GB allocation. C2E2 needs ~8 GB total system RAM to run well; on an 8 GB-total PC, lower Prism → Settings → Java → Memory to 4096 so Windows isn’t starved.
Install printed an unexpected error and bailed
Re-run the one-liner — most failures are transient (network blip during the modpack zip download, winget mid-update). If it keeps failing, screenshot the error and DM the admin.
Connecting to the server
Problem
Fix
You are not white-listed on this server
Your UUID isn’t on the allowlist yet. DM the admin with username + UUID.
This server has mods that require Forge to be installed on the client
You launched the vanilla Minecraft launcher instead of the Prism C2E2 instance. Launch from Prism.
Connection timed out
Server may be down or restarting. Wait 2 min and retry.
Outdated client / Outdated server at the FML handshake
Your modpack version doesn’t match the server’s. See Updates — usually fixed by double-clicking the Update Craft to Exile 2 launcher (or running nz update).
Server name in the server list shows a different version than your instance
New modpack version is out and your client hasn’t picked it up. Double-click the Update Craft to Exile 2 launcher — see Updates.
Connected but instantly disconnected
Usually a mod-list mismatch. Run nz update (the Update launcher). If that doesn’t help, re-run the install one-liner — it does a clean reinstall preserving your state.
Launching the game
Problem
Fix
Prism shows MODPACK VERSION MISMATCH and refuses to launch
This is the launch-time version check (nz check). Close Prism and double-click the Update Craft to Exile 2 launcher — full walk-through in Updates.
Prelaunch printed Could not fetch latest version (...); allowing launch.
GitHub raw or your internet is briefly unreachable — the check fails open and lets you launch with whatever you have installed. Server will kick you at FML handshake if your mods don’t match the current pinned version. Re-try later.
Prism shows PreLaunchCommand failed and won’t launch
The version-check hook crashed. Re-run the install one-liner — it reinstalls the hooks and nz.exe. If still broken, uncheck Custom commands in the instance’s Edit → Settings → Custom commands tab as a temporary workaround (server may kick you if mods are out of date), then re-run the installer.
Game crashes on launch
Most common cause is too much memory allocated, not too little. Prism Settings → Java → Maximum memory: try 4096 first (especially on 8 GB systems). If that fails, confirm Java 17 is selected and send the crash log to the admin.
Custom mods or pack-owned config tweaks reverted after update
Updates delta-sync tracked modpack files with packwiz so your client matches the server. Personal state and preserve-list configs should stay in place. If you want to test custom mods locally, uncheck Custom commands in the instance’s Edit → Settings → Custom commands tab (you won’t be able to connect to the live server while it’s unchecked).
Open Task Manager while playing — if RAM is maxed, lower Prism’s Memory allocation by 2 GB and restart.
Long stalls on world entry
First-time chunk loading. Improves dramatically once the area has been explored once (Xaero map cache warms up).
Backups
Problem
Fix
Prism takes a long time to show “Stopped” after quitting the game
A backup snapshot is in progress (runs at most every 3 days; takes ~10–60 s depending on explored-map size). Check %APPDATA%\PrismLauncher\instances\Craft to Exile 2\.negativezone\nz.log to confirm. To disable, see Backups → Tuning or disabling.
Lost a waypoint / world / setting after a recent update
Restore from a snapshot under %APPDATA%\PrismLauncher\instances\Craft to Exile 2\.negativezone\backups\ — see Backups → Restoring user state from a snapshot. The update step forces a snapshot just before every upgrade, so there’s always a fresh restore point.
Empty / 0-byte snapshots in .negativezone\backups\<ts>\
Should be fixed in v0.4.2+; if you see one in a freshly created snapshot, run nz support and DM the admin the resulting zip (it includes nz.log).
Old Craft to Exile 2.bak instance I want to delete
Right-click → Delete instance in Prism (or delete the .bak folder). The next upgrade creates a fresh one.
Collecting logs for the admin
Every nz command writes a full-detail record to nz.log inside the instance’s .negativezone\ folder (%APPDATA%\PrismLauncher\instances\Craft to Exile 2\.negativezone\nz.log). First-install logs (before the instance exists) land in the global fallback at %LOCALAPPDATA%\NegativeZone\nz.log.
Need
Do this
Send everything the admin needs in one file
Double-click the Update Craft to Exile 2 launcher’s folder and run nz support (or "…\.negativezone\nz.exe" support). It writes nz-support-<timestamp>.zip to your Desktop — DM that to the admin.
See more detail on the console while a command runs
Add --verbose (e.g. nz update --verbose). nz.log always contains the full detail regardless.