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E08 just means that there is a heating issue with your oven. It's not really specific as to which can cause the problem since there are many possibilities. But lets see if we can narrow it down. Do you have a multimeter to make any electrical tests? And does the oven heat on any setting at all (bake/broil/etc...)? This would also tie in with the flashing PrE that you see. Your oven cannot preheat it's self.
What you're looking at is either a bad element (if just one of the heating functions doesn't work), or possibly a bad high limit thermal cut out if your model has one. You can also have a bad oven sensor or bad control board. You can't test the board but you can test the sensor. Open the door and remove the 3-4" long thin metal rod attached to the back wall. There are 2 screws holding the sensor on that you can remove and then pull the sensor forward until you can disconnect it. With a multimeter, check the resistance of the sensor at room temperature and it should be about 1080 ohms. If it's not, replace the sensor, otherwise you need to replace your relay board.
If you have any other questions, please let me know. I wish you the best.