I am able to download the sketch to Port3 and have Modbus pointed to Port5 but the PLC IDE freezes every time and I get the Com5 server message in this screenshot. I've seen other posts with similar issues but can't seem to find a resolution. Windows 11 Home 24H2 - HP Laptop
All set - the recommended tutorial did the trick:
tutorial Opta™ Memory Partitioning for Use with the Arduino IDE.