Addie finished in 26th place following rounds of 74, 70, 70 and 75 for a five over par total of 289.
The championship was won by Welsh player James Ashfield (Delamere Forest) with a seven under par total of 277.
The two other Ayrshire players in the field missed the halfway cut, which fell at two over par.
Ruben Lindsay (Ayr Belleisle) had a four over par total of 146 following rounds of 72 & 74 whilst Alyx Murray (Prestwick St Nicholas) had a nine over par total of 151 after rounds of 77 &74.
In the corresponding Girls' event, played on the same dates over the Eden Course at St Andrews, there was a Scottish winner when Hannah darling (Broomieknowe) recorded a four under par total of 209.
Ayrshire's two representatives in the field both failed to make the cut for the final round, which fell at 13 over par.
Clair McLaughlin (West Kilbride) had rounds of 89 and 80 for a twenty seven over par total of 169, whilst Rachel Foster (Prestwick St Nicholas had an opening round of 81, ten over par, before retiring from the competition.