Source note: LemonLoader is independent. Project-specific facts below are limited to information published by the LemonLoader repository, releases, or wiki; general troubleshooting advice is identified by context.
Why backup comes first
The installation wiki explicitly warns that on-device patching removes app data. That makes a backup plan a prerequisite, not an optional optimization.
Backup checklist
- Identify whether the app uses local saves or required OBB files.
- Use the app/game’s supported cloud or export feature when one exists.
- Copy accessible files that the app documents as portable.
- Record the installed version so you can return to a clean copy.
- Do not assume the installer can restore every data type.
Windows installer nuance
The wiki says the Windows installer can automatically back up app data during patching, but also says it currently cannot restore that app data automatically. Treat the backup as a safeguard, not a guaranteed one-click rollback.
When not to patch
If you cannot afford to lose local progress or required files and you do not have a verified backup path, the safest choice is to postpone patching.
Build a rollback plan
A useful rollback plan answers three questions before any patch starts: how will you reinstall a clean copy, where is important data stored, and which data can actually be restored? If one of those answers is unknown, investigate it first. The official warning about app-data removal makes this preparation especially important for titles with local saves or additional content files.
Record the starting state
Write down the app version, LemonLoader release, device, and whether the app currently launches cleanly. If possible, test the unmodified app immediately before patching. That gives you a baseline. Without it, a pre-existing crash can easily be misdiagnosed as a LemonLoader problem after the patch.
Keep backups separate from the files the installer is about to modify. A backup stored inside an app directory that is removed during patching is not a useful backup.
Recommended next step
For a clean path through the project, use the verified download page, follow the installation guide, and keep the logging guide available for troubleshooting.