Problem with disappearing Blueprints when deactivating mods [1.1.91]

[felixb1808]

Lately, I accidentlly started a vanilla world with mods activated.
Now some of the Blueprints are missing, which I noticed too late.
More precisely, I am missing the nuclear reactor.
The mod I used is called "Realistic Reactors".

How it should be:

blueprint.png (6.99 MiB) Viewed 290 times

How it is (The reactor is missing):

noBlueprint.png (6.01 MiB) Viewed 290 times

Also, I made sure, that I really have the needed research:

research.png (2.79 MiB) Viewed 290 times

I don't know what to do and I still want to be able to earn achievements.

Please help.

Best regards.