If a red triangle is displayed during PLC detection and the solution cannot be uploaded to the PLC - Error message "Target device contains old runtime, update is required"
it is necessary to right-click on the PLC in the solution, select "Operations with PLC" and "Upload RT". After a successful RT upload, reassign your PLC to the solution and upload it to the PLC.
If for some reason the PLC refuses to start the uploaded project, to "resuscitate" the PLC, lift the DIP switch "STOP RT" and upload an empty project (newly created) to the PLC. This project will not start on the PLC due to blocking of the runtime start by the HW switch (DIP switch for stopping RT is activated). Now set the DIP switch for the RT assembly to the default position in the "OFF" state and re-upload the empty project to the PLC, which should already start on the PLC.
PLC LED RUN diodes can signal a certain error - more in Error codes LED RUN flashes.