No possibility to create a new account

Our potential Programme Committee members and those who want to submit a talk are not able to create it - once you put all the details to create a new account you get a 500 internal server error. (url
<img width="1422" alt="Screenshot 2021-12-13 at 16 37 36" src="https://user-images.githubusercontent.com/64010162/145841734-f8e96f5d-d573-4f9a-8eb8-5b25a22639d7.png">
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