2002 mercury stuck in neutral

[magicman1223]

I have a 2001 Tahoe q3 with a 2002 mercury 125 Outboard. Last summer everything was great except one time I pushed the button to put the motor in "throttle only" and it would not come out of throttle only until I pulled on a little plastic pin that was behind the button for "throttle only" Other then that all last summer everything was great. Today I took the boat out to troll around the lake a little bit and pushed the "throttle only" this time however it would not come out of it for anything.

Does anyone know what to look for in order to fix the neutral issue?