Debbie Goss-Ross

I had the mecer inverter Sol-i-ax-5kp installed in January 2021.. we haven't had nearly as many power outages as most other areas but today it happened .. I let the inverter do its work for about 3 hours and then decided to put my generator on to charge the inverter batteries.. the generator ran for about 4 hours and when I switched it off back to the inverter it wasn't long before the inverters alarm went off and switched the inverter off.. so I switched the generator back on but then the inverter kept going on and off ie lights on then dipping and when I looked at the inverter the fault light was flashing..and showing the error code H5. Please can someone advise me.. I'm a widow .. with my elderly father very little resources and I have no idea why this is happening and the installer is no where to be found!