I'm not able to open any packages. I've tried both to repair Studio and to uninstall/re-install. Nothing seems to help.
Looks like a Worldserver dll is missing.
Try to reinstall the world server components:
1. Make sure all SDL applications are closed.
2. Go to C:\ProgramData\Package Cache\SDL\SDLTradosStudio2017_SR1\modules.
3. Run the WorldServerComponents.msi installation file.