Thankyou for the immediate repply.
1. this problem appen on different machine and to different custommer. I never connect via teleservice when it appen, because sometime it need much time: However in the future I will do to check the diagnostic buffer. I could ask to custommer to save the buffer using NCK selector.
2. in the picture attached there is the configuration of the last CPU where is appened the problem today (normally we save this picture before to install the new machine, but I don't know exacly in wich other machine appened the problem, I have to ask to our service).
3. I can exclude that is the custommer to delete the user folder, because they are connect to the machine only by an MP277