If your i1 is failing the reflectance calibration test in i1Diagnostics, there are a couple of things you can try to remedy the situation.
Make sure that your calibration tile is clean and free of debris.
Try plugging your i1Pro into the USB ports on the back of your computer or try using a powered USB hub. The i1Pro requires a great deal of power from the USB port and power fluctuations may cause the lamp to fire incorrectly.
If neither of these steps correct the problem it will need to come into our facility for service. X-Rite provides a one-year warranty on the i1Pro with proof of purchase. If your device is out of warranty, the flat rate for repair will apply.