If you play with mods you patched yourself, an update can replace your patched build with the official one without you noticing, and playing on can lose what your patch added to the save.

Patched Mod Guard remembers in each save which mods ran as your patched builds. When one of them is active without its patch after loading, it pauses the game and lets you choose:

• Go back to your patched build: exit to the main menu without saving, install it, and load the save again. The save stays untouched.
• Use the current version from now on.

How to use

In your patched build, add a hidden startup setting to settings.lua. <mod name> is the internal name of the mod, as in its zip file name.

data:extend{{type = "bool-setting", name = "patched-mod-guard-marker-<mod name>", setting_type = "startup", default_value = true, hidden = true}}