Hello everybody, I’m Michael from Germany and I’m trying to set up my home automation with HomeAssistant on a brand new Raspberry Pi 4 Modell B, 4GB. First I added a ZigBee USB stick and I’m controlling some lights with it, all fine so far.
Then I got myself a HmIP-RFUSB stick because I want to control some blinds by HomeMatic actors. I did all as suggested in some tutorials, but soon after I started to check the CCU surface I got the error message from HmIP-RF telling me that a component of the HomeMatic device is not working anymore. It suggests to check the network connectivity or power supply, or at least one component of the HomeMatic device crashed.
About half an hour after it got started the HomeMatic addon crashes completly and needs to be restarted.
Now I did some research in the HomeMatic CCU’s Log. Soon after it starts I get the first error telling:
2020-07-25 13:28:29,742 [ERROR] BidCosRpcDispatcher - BidCosCache could not be initialized
2020-07-25 13:28:29,742 [ERROR] BidCosRpcDispatcher - java.net.ConnectException: Connection refused (Connection refused)
Then I get the [ERROR] BidCosRpcDispatcher – Could not register BidCos-RF_java a lot and right before the final crash it looks like this:
> *2020-07-21 14:49:40,219 [ERROR] BidCosRpcDispatcher – Could not register BidCos-RF_java*
> *172.30.32.2 – – [21/Jul/2020:14:49:41 +0200] „POST /api/homematic.cgi HTTP/1.1“ 200 89 „-“ „Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0“*
> *172.30.32.2 – – [21/Jul/2020:14:49:42 +0200] „GET /ise/img/homematic_logo_small_red.png HTTP/1.1“ 200 22405 „-“ „Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0“*
> *172.30.32.2 – – [21/Jul/2020:14:49:42 +0200] „POST /esp/system.htm?sid=@cwApNIpljW@&action=UpdateUI HTTP/1.1“ 200 429 „-“ „Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0“*
> *[14:49:44] INFO: 2020-07-21 14:49:44.979 Run SetInterfaceClock now.*
> *Error in XmlRpcClient::writeRequest: write error (error 111).*
So it seems there is some problem with the BidCosRpcDispatcher keeping it from registering it’s BidCos-RF_java - but what can it be?
I even tried to set up HASS completly new by flashing my SD card again, and only add the HomeMatic addon. Same problem again. So I’m really running out of ideas what the problem could be and I’m hoping to find some help here 
Greets, Michael from Germany