"An element with the same key has already beeen add" 4-27

So i want to finally build my game, and i have this error

And i honestly don’t get it at all.
My project is already in another folder then 4.27, so… i’m totally lost.
I’ve tried to verify unreal, all good. Deleted the plugins and the save folder (but this one is re-created everytime you open the project)

Any idea ?

When I got this error, I had two copies of the same plugin.

I’d upgraded the plugin manually, but kept the original just in case.

Even though I renamed the folder, the plugin was called the same thing…

When u say upgraded you mean change the name from “plugin” to “plugin1” ? Or something else ?

No. I got a ‘hot’ copy from the plugin writer. I went into the plugins folder, renamed the current plugin folder to ‘plugin-name’-old ( or something ), and then manually installed the new version.

The upshot of this, was I had two plugins with the same name, even though they were in a different folder hierarchy.

This gave the same error.