There is nothing wrong with the run time system. You have a bug. Make a debug version (compile with.... -d I think?) and step through your program.

Now, the RTS is simply starting up and quitting, no explanation, just start up and die. This all started today, or at least recently, and I don't understand what's wrong or why everything has changed suddenly. First the compiler stops working, my storage area keeps tripping everything to read only, now the run-time system is going into instant quit mode.

This is weird and makes no sense.