Hi, Welcome to the Forum Sebastianquerey !
Here are all important links:
viewtopic.php?f=1&t=4740
-A few rules and useful forum instructions
You mention several 'things' i dont know, so i think you are on Linux -right?
after cleaning and maintenance in my pc, with stacer. The Calf FX disappeared in my LMMS.
I try to uninstall and install again LMMS but nothing happens.
Please help me.
Since a lmms-'reinstall' have not fixed your issue, then it must be a linux-dependency, that has been removed in your cleanup. I believe there are some ways to make a diagnostic for core-functions of linux, but it is really more a question you should aim at a forum for your linux-distro/ pacMan
The only lmms-related thing i really want to ask you, is weather or not you use a distro-lmms or our off. AppImage?
I strongly advise you to use our AppImage
https://lmms.io/download/#linux
Let us know the outcome :)