Also, instead of READ_PHONE_STATE permission, try to ask for android.permission.READ_PRIVILEGED_PHONE_STATE because the GetImei and GetMeid blocks require that permission, and make sure its granted.
Also, do you even have a IMEI number ? 
(If you don't have a sim slot, more chance is there that your device has no IMEI number...)
Also, this link might help...
Deviceid function of the phone manager extension no longer returns the id.