Problem with TeamViewer 12

Hello everyone, I use TeamViewer without any problem (version 12.0.82216) on my 3 PC. One is in Windows XP Pro SP3 and the other two in Windows 7 SP1. But for a few days I have a black screen on the other 2 PCs: I SEE BLACK SCREENS ON THE 2 PC DISTANSTS. I specify that the connection is done well BUT NOTHING on the screen. Would anyone have the same problem and could help me? Thank you in advance and good day.