No Camera release from 4.8.3

CO 4.8.3 worked fine, suddenley it stopped to release my p45+ (System 10.5.😎. I schwitched off the camera, put the batterys out of the camera, restarted the back, disconnected the back, put out the battery of the back, restarted CO, restarted the MacPro, threw away the phaseone.com.plist. Still no positive result. Camera won`t be released.
Any suggestions?