HP 17bII+ - Manual (Page 288)

288 Error Messages
File name : English-M02-1-040308(Print).doc Print data : 2004/3/9
No solution was found for a Solver equation using the current values
stored in its variables. Refer to page 246 in appendix B.

A warning
－not an error－that the magnitude of a result is too small for
the calculator to handle, so it returns the value zero. See page 47 for
limits.

 
Attempted a two-list SUM calculation using lists of unequal lengths.