Riding Lawn mower wont walk into gear? Have a ACE Limited Edition 18.5hp lawn mower that starts right up...

Have a ACE Limited Edition 18.5hp lawn mower that starts right up but iam unable to put surrounded by to gear,knob goes forward&reverse but nothing happen, its like it in nutural but it not mete out u cant even psh it. Thought it might be the parking break, but i dont beleive it is because that dose release when pulled. ANY HELP??Thanks,Karen
I own of late cracked a turquoise hip...
Answers:    if its in gear the safety switch will not tolerate you start the mower
Damp still present after mushy coursing. Has cause...
If it's a hydrostatic transmission...check the fluid level.