If your Passiv Programmer shows either of these error messages, this means that connection to that Thermostat has been lost.
If you have wireless Thermostats, this could be caused by the Thermostat running out of charge. You can determine whether you have wireless Thermostats by a battery icon on the top right of the Thermostat display, or via the USB C charging port at the bottom of the device. If the Thermostat is out of charge, follow the instructions in this article on how to recharge the device. If the Thermostat is already charged, it may be struggling to connect to the Programmer. Try moving the Thermostat closer to the Programmer (you may also need to remove the backplate from the wall to keep the Thermostat attached). If this fixes the connection issue, see if you can relocate your Thermostat closer to the Programmer. Otherwise there may be an issue with the Thermostat and you will need to contact your installer.
If you have wired Thermostats, this is likely an issue with the wired connection between the Thermostat and the Programmer. Contact your installer to investigate further.