Excessive Boost Converter Output
EDIT - in case any other potential downvoters miss the point - the original question had R4 as 100 ohms and asked if there was something wrong on the schematic (it now says "circuit")!!

It looks like R4 is the wrong value i.e. far too low. It forms a potential divider with R3. With the values shown it has an attenuation of 0.00124. In normal operation you would expect to see 1.26V at the FB (feedback) pin. With your attenuator this implies a line output voltage of about 1,017 volts.

Here's an example from the data sheet for a 48 volt output: -



Note the ratio of resistor values surrounded by the red rectangle. They attenuate by a factor of 38.35 and with 48 volts on the output, the voltage on FB is 1.252 volts. Given that it should be 1.26 volts (according to the data sheet) I reckon this circuit will produce 48.3 volts.