I just experienced a similar issue starting last week. It runs for 20-40mins, then shut-off the lamp and fan and blink red light like it is a lamp failure. I think it is overheating though!
There is an option in the menu, high altitude, that runs fan at full blast if selected. I tried that and the malfunction didn't occur (I tried only twice, so I need more hours of testing!). This makes me think that at normal speed the fan is not cooling off the projector anymore. Potential reason could be dust inside.
The projector has two years and less than 300 hours as well.
Did you fix your problem?
Overheating makes the most sense, since the projector restarts just fine after unplugging electricity for 1 min.
Curios to know if you fixed your issue.