Can't turn any knob / cant use internal cubase plug ins

hi! i have the latest cubase version installed. when i load/open a cubase internal plug in i cant turn any knob ob the plug in. so i cant use any one anymore. all 3rd party plugs work perfect.

the issue appears on all internal cubase plug ins - delay/reverb etc.

i really dont know what to do. this way i cant work with cubase anymore as i love to use the internal plugs. :cry:

any help ?

thank you!

Try to repair installation or re-install.