Opening an old Unity project containing 2d game kit

Hey folks,
i programmed a 2d platformer in 2018 using Unity 2018.2.8f1 (64-bit) and the unity 2d game kit. I was now trying to open the old project folder with the same version using the unity hub.

Besides i can open the project itself, the result is quite disappointing: most of the elements are not loaded in the correct way: missing sprites, object, prefabs and so on. The game kit itself also doesn’t work as it should: models are missing, terrain is pink and things like ‘create new scene’ don’t exist anymore. I tried re-importing the kit after loading my project, but it tells me that everything in this package already exists. Does anyone know how to solve this problem?

Thank you in advance,
Einsteins Ente

Screenshots

Did you put everything you needed under source control when you saved it? Sounds like maybe metafiles didn’t make it over…

Metafiles are all there. Sorry for the late reply.