Where possible, it's recommended to not use PPAs at all. Adding a PPA is essentially giving the owner of the PPA root (administrator) level access to your system. It is possible for them to maliciously or accidentially replace system packages with broken/unpatched/malicious versions.
PPAs by trusted vendors are probably fine (Ubuntu, Libreoffice, etc), ...
to delete a uncompatile or bad repository try this command in the termnial
$ sudo nano /etc/apt/sources.list
when nano is openned, remove that bad repository (manuelscheider) and press
Ctrl + O to save and Ctrl + X to exit.
After this operation run this command in the terminal
$ sudo apt-get update && sudo apt-get upgrade -y
And that is all. I hope ...