PLC IDE 1.0.8 not conneting to Opta RS485

I just bought an Opta RS485 for a project. I have been struggling for four days to get the IDE to connect with the Opta and it does not work. I have tried everything and I am on the verge of giving up. Unfortunately I can't sell or return this item as it's not broken.

I have tried all the tricks I found in the different forums:

  1. I tried QSPI format (both in "heartbeat" mode and normal mode)
  2. I tried installing the runtime (both in "heartbeat" mode and normal mode)
  3. I tried a different computer
  4. I tried switching off all security features (firewall, antivirus, etc.)
  5. I tried installing and running the IDE "as administrator"
  6. I tried deleting all the files in folder T
  7. I tried IDE version 1.0.6 and 1.0.8
  8. I tried three different kinds of USB cables
  9. I tried with 24V on and off
  10. I tried using different combinations of the ports, baud rates and parities.

None of the interventions above worked.

Can someone help please? My project would be impractical if I tried to use the normal Arduino IDE.

If anyone was able to set it up properly, please help.