Jenny Mod Crashes: Diagnosis and Fixes

Start with the first useful error

Write down exactly when the crash occurs: before the launcher opens, during Forge loading, at the main menu, while opening a world or when a character appears. Those stages point to different causes, so avoid changing several things at once.

An exit code such as 1 only confirms that the process stopped. Open the log and search upward from the final lines for the first clear message containing terms such as missing dependency, incompatible version, duplicate mod, Java heap space or a named mod ID.

• Crash before the Mods screen: check the selected profile, Java runtime, Forge build and dependencies.
• Crash while opening one world: test a new world before changing the original save.
• Crash when an entity or effect appears: test without shaders, resource packs and unrelated rendering mods.
• Every Forge profile crashes: test a clean Forge profile with no mods to separate a loader problem from a mod conflict.

Confirm edition, Minecraft version and loader

A Java Edition Forge .jar cannot run as a Bedrock .mcpack or .mcaddon, and changing the extension does not convert it. This crash guide is primarily for the Java Edition Forge route; Bedrock import and activation problems use a different diagnostic path.

Check the exact Minecraft version shown by the launcher profile, the Forge version attached to that profile and the version information inside or supplied with the mod file. Do not choose the newest Forge release by name alone. Forge builds belong to specific Minecraft version lines, and a mod can also declare loader, game or dependency version ranges.

• Launch the intended Forge profile rather than the normal Minecraft profile.
• Keep the mod as an intact .jar in that profile's actual mods folder.
• Remove duplicate copies and files built for another Minecraft version from the test profile.
• If the file's target version cannot be identified, do not guess by repeatedly launching it.

Find the crash report and latest.log

Open the game directory used by the failing profile. The newest file in crash-reports records a crash when Minecraft created one. The logs folder normally contains latest.log, while Forge support may also request debug.log because it includes more loader detail. A failed launch does not always produce a crash report, so latest.log or debug.log can be the better record.

Read the complete error context, not only the last line or the launcher message. Keep your account name and local folder path private when sharing a log, and never include launcher tokens or credentials. Forge support asks for the full current log and the latest crash report when one exists.

• Windows default profile: open the selected installation's game directory instead of assuming every profile uses %appdata%\.minecraft.
• CurseForge profile: open the profile folder, then check logs and crash-reports.
• Look for the earliest explicit failure and note the mod ID, required version and exception name around it.
• Save the untouched log before another launch replaces latest.log.

Test missing dependencies and mod conflicts

If the log names a missing mod or an unacceptable version range, resolve that exact requirement from a traceable source. Do not install a random library because another guide uses it; dependencies can differ between builds.

For a conflict, make a separate test profile with the same Minecraft and Forge versions. Start Forge with no mods, then add the Jenny Mod file and only dependencies confirmed for that file. If it loads, restore the remaining mods in small groups until the crash returns. The last group narrows the search without risking the working profile.

• Keep a list of every removed file and its version.
• Change one group at a time and launch after each change.
• Do not test a suspected conflict in an important world.
• Treat a mod named near the bottom of a stack trace as a clue, not automatic proof; inspect the first causal error.

Check Java and memory only when the evidence points there

Use the Java generation required by the Minecraft and Forge version in your profile. Forge documentation maps Minecraft 1.12 through 1.16 development to JDK 8, while newer Minecraft lines use later Java generations. Replacing Java blindly can fix one profile and break another, so confirm the active executable and version first.

If the log contains java.lang.OutOfMemoryError or Java heap space, close heavy background programs, remove optional shaders or large resource packs and review the profile's memory setting. Oracle explains that Java heap space can mean the configured heap is insufficient, but it can also indicate another memory problem. Do not assign nearly all system memory to Minecraft or increase memory when the log shows a version or dependency error instead.

• Confirm whether the launcher uses its bundled runtime or a custom Java path.
• Remove obsolete custom JVM arguments before testing a clean profile.
• Record the current memory value before changing it so you can reverse the test.
• If the error mentions native memory, graphics drivers or an access violation, increasing the Java heap may not address it.

Match the fix to the crash stage

Use the stage and the first causal message together. A version rejection during Forge loading needs a version correction; a crash only when entering one world needs a safe world test; an error triggered by a visual effect calls for a minimal graphics test. This is more reliable than applying every popular fix in sequence.

• Forge rejects the file: match Minecraft, Forge, the mod build and its declared dependencies.
• Main menu works but a world crashes: back up the save, test a new world and remove optional content from the test profile.
• Crash begins after adding another mod: restore the last working set and reintroduce the new files in small groups.
• Black screen or rendering failure: test without shaders and custom resource packs, then verify the GPU driver from its manufacturer.
• OutOfMemoryError: reduce optional load and adjust memory carefully after confirming the exact exception.
• No crash report: use latest.log or debug.log from the failed session.

Repair the profile without deleting your worlds

Copy the saves folder and the profile folder before repairing anything. A clean profile is safer than deleting the original installation because it preserves the failing setup for comparison and keeps worlds available for recovery.

Create a profile for the intended Minecraft version, run it once, install the matching Forge line and confirm Forge reaches the menu with no mods. Add only the identified mod file and verified dependencies. Open a disposable test world first. If that works, move a copy of the affected world into the test profile and check it separately.

• Do not delete saves, screenshots or options while diagnosing a loader failure.
• Do not overwrite the only copy of a world with a test profile.
• Keep the last working mod list beside the backup.
• Use CurseForge's Repair Installation only for an app or installation problem; it does not resolve an incompatible mod combination by itself.

Prepare a useful support report

If the crash remains, record the Minecraft edition and version, Forge version, Java version, launcher, exact filename, crash stage and the most recent change. Include the full latest.log or debug.log and the newest crash report if one was created. A complete report is more useful than a screenshot of Exit Code 1.

Describe the result of a clean Forge test and a minimal-mod test. This shows whether the failure follows the loader, this file, a dependency, another mod or a particular world, and prevents helpers from repeating steps you already completed.

• Remove usernames, access tokens and private paths before sharing.
• Share plain-text logs through a reputable paste service rather than screenshots.
• Do not edit out error lines because they look unrelated.
• State every troubleshooting change and whether it altered the result.

Frequently asked questions