If you have installed an update of ProCall and no presence information is visible in the ProCall client monitor, but it is still displayed correctly in the ProCall main window, this indicates an error in the update process.
Exit the ProCall client.
On the UCServer, rename the ClientContent file(s) of the affected users under C:\Programs\ESTOS\UCServer\config\users\xx_clientcontent.xml,
On the respective ProCall client, delete the ClientContentCache file under %APPDATA%\ESTOS\ProCall 4\email@example.com_ClientContentCache.xml and – if still present – the favoritessearchcache.db file.
Restart the ProCall client.
Reconfigure contacts in Favorites and Monitor.