If you saw the following message and reached this article, we're here to help!
This error happened since you added an incompatible mod to your projects' modloader, (whether manually or through the app) or updated an existing one to a later version that is incompatible.
To fix this, you will need to either update again by clicking the downward arrow icon, or download a previous, compatible version.
What are the differences between the Modloaders?
When browsing for Modpacks, editing projects or adding more contents, you might have seen a distinction between Forge and Fabric.
In short, these are two different modloaders that help enable Minecraft modding as you know it in the CurseForge app.
When authors submit their mods, they mark which modloader the mod is compatible for, and they might add files to support both modloaders.
When you edit a project or create a profile- you should keep in mind the modloader type, so that you only add mods compatible with that modloader!
Note that not all mods are available for both modloaders, this may affect which project type you prefer to create.