@fantasyfanatic - please review the contract section of the rulebook. With a winning bid of $18m, you have the following options:
1 yr $18m AAV
2 yr $9m AAV
3 yr $6m AAV
4 yr $4.5m AAV - not allowed, AAV is too low.
5 yr $4.0m AAV (rounded up from $3.6m AAV) - not allowed, too low.
Please submit a revised contract length - thanks!