Thanks Chris for your reply and support.
I would say there are good new and “not too bad news”, at least there is hope 
And sorry for my stupid question… how can I check if I’m using the old dingz device. I followed your instruction, deleted the app from homey and re-installed the latest version, every firmware (I have 5 dingz installled) is latest version.
So if you have deleted the dingz app and reinstalled everything, you will automatically only have ‘new’ devices.
BDW: The migration (except for the sensor) would have been done by the dingz app itself the first time it was started. >> ‘RTFM’ 
I “RTFM”.
Did it once again, first deinstalled, then followed exactly the installation. Result: Dingz appears in the app section
Homey 101 > Refresh the page 
…
Finally the sequence “Uninstall dingz app – shut down and restart homey – install dingz-app” worked.
Hi Chris
I can’t get any further. I always get the same error message: MQTT: Connect Econnrefused 192…: 1883.
I can’t get any further.
Many thanks for your help
- Some change
Hi Chris
I have installed the app and could set it up. After I played around I did restarted again with a new setup (factory reset of homey) and then when installing the Dingz device I get an error “dingzSwitch error AxiosError: Request failed with status code 500” when the installation whats to show the available functions of a dingz device. The ones not yet installed in the first try are working…
I tried to restart the dingz / power off / restarted the dingzSwitch…
Currently end of my ideas… Do you may have one?
thanks and regards
Tadzio
I’m missing some info (aka RTFM)
BDW: The error (500 = Internal Server Error) isn’t coming from the app, but from the MQTT broker or the switch itself.
RTFM was done properly… As first installation was working 
looks like this is a Dingz problem, as on the DingzApp the item is also not more shown. Try no to reinstall the Dingz Controller again… But somehow I did kill them by trying to install the dingzSwitch on Homey…
But anyhow… Many thanks for your huge work on programing this app!!
Regards Tadzio
BDW: You can always reinstall the app over an existing installation without losing your configuration and flows. Only deleting it and reinstalling it is “fatal.”
?