Set Note Password function error

What could have been the reason why I keep on receiving an error message GVM0108E when performing the Set Note Password function? I really don’t understand. I really find the message so confusing. Can you please at least tell me what should be done so that I can proceed successfully? Or maybe you could probably explain the meaning of the error message below.
Error: GVMIOBE Set password failed. Error: ANS1025E (RC137) Session rejected: Authentication failure
Thank you.
