IMU stops abruptly, is it dead?

Check if there are pullups installed on your board (your supplier unfortunately doesn't supply schematics for the product). Disconnect the breakout from your Arduino and measure the resistance between Vcc and SDA/SCL with a multimeter. Post the results.

Error 2 means that the device didn't react on the I2C bus, so it's possible that your device got broken, although I cannot see a reason at the moment.