Datasmith plugin inactive in old scene


So I wanted to continue working on a project that was created in 2018. Coming from 3ds max, I use datasmith to import my model into Unreal Engine. So I would make changes on the model in 3ds max and just reimport the scene, normal workflow. Works in every other project.
However, we have had some changes in our infrastructure and the datasmith assets are now linking to a server path that doesn’t exist anymore. So the assets are there, but the source files can’t be found. I see everything in my scene though, which I find awkward. Considering the .uedatasmith-file, I can see that it links to an inexistent path. I cannot reimport or set up a correct path for the datasmith file, it just says “Failed loading asset”.
So naturally, I considered importing a whole new uedatasmith-file and deleting the old content, when I noticed there was no more Datasmith-Import button and the importer plugins are inactive and greyed out.

The plugin works fine in a newer file I have recently created.

So what happened here? Why is the datasmith plugin not working in this particular file? And how can I reactivate it?


Alright, I knew I was too tired for this.
you will find the solution for my problem if you scroll all the way down to the bottom of the following page: