Fronius integration suddenly stopped providing some entities, rest is fine | Home Assistant | Page 1

Summary: After years of working just fine, yesterday at 21:12 the integration suddenly stopped providing all entities in it's SolarNet device, showing as unavailable now. But all others are fine, and the (local) API endpoint that delivers the data is also fine and has all the data it always has.

Details: The Fronius integration (part of HA Core) brings data from their (solar) inverters and associated devices into HA. It creates multiple (virtual) devices that represent different aspects (inverter, battery, meter), one of them being the SolarNet, which contains all the power flow and usage. All of the data comes from the SolarAPI that is a fully local endpoint, providing the raw values. Basically one for each of the HA devices. All HA entities belonging to other devices work perfectly fine. Looking into the SolarWeb (online portal of Fronius) I cal also see the power flow just fine.

To be clear: there was no update to the firmware of the inverter. The last HA Core update was ~24 hours before this, and afaict it didn't contain any changes related to Fronius. I did restart both HA and (much later) the inverter as well, with no changes.

Hardware: Symo GEN24 8.0 (ROW 1.37.6-1), BYD Battery-Box Premium HV (7.68 kWh), Fronius Powermeter at Grid interconnection point.

Screenshots are attached, showing both the SolarNet (not working) and SmartMeter (working).

Digging for logs was not very successful, since HA doesn't save logs anymore since I think november of last year or so. But I did find one line in the Docker logs of the HomeAssistant container itself:
2026-03-25 21:12:12.367 ERROR (MainThread) [homeassistant.components.fronius] Error fetching fronius_power_flow_Fronius-Gen24.<domainname_censored> data: An error occurred while attempting to fetch data: BadStatusError at GetPowerFlowRealtimeData.fcgi. Code: 255 - UnknownError. Reason: Internal error..

Any way to un-break my SolarNet?

Oh I forgot: this is a data sample of the endpoint in question, coming from the inverter at /solar_api/v1/GetPowerFlowRealtimeData.fcgi:

   "Body" : {
      "Data" : {
         "Inverters" : {
            "1" : {
               "Battery_Mode" : "normal",
               "DT" : 1,
               "E_Day" : null,
               "E_Total" : 12159620.18111111,
               "E_Year" : null,
               "P" : 816.9652099609375,
               "SOC" : 97.299999999999997
            }
         },
         "SecondaryMeters" : {},
         "Site" : {
            "BackupMode" : false,
            "BatteryStandby" : true,
            "E_Day" : null,
            "E_Total" : 12159620.18111111,
            "E_Year" : null,
            "Meter_Location" : "grid",
            "Mode" : "bidirectional",
            "P_Akku" : 765.79876708984375,
            "P_Grid" : -24.100000000000001,
            "P_Load" : -793.03720703124998,
            "P_PV" : 108.58460235595703,
            "rel_Autonomy" : 100.0,
            "rel_SelfConsumption" : 97.050678907700458
         },
         "Smartloads" : {
            "OhmpilotEcos" : {},
            "Ohmpilots" : {}
         },
         "Version" : "13"
      }
   },
   "Head" : {
      "RequestArguments" : {},
      "Status" : {
         "Code" : 0,
         "Reason" : "",
         "UserMessage" : ""
      },
      "Timestamp" : "2026-03-26T16:56:51+00:00"
   }
}

#Fronius integration suddenly stopped providing some entities, rest is fine