chain too tight or something is seized up
No, it wont.
its broken !! take it to a mechanic
Shift linkage may need to be adjusted?
It might be the brake pedal switch
Wont shift while engine is on? Is it an automatic or a manual? if you put more information I can put a more reasonable answer.
When not used, they do get stuck and hard to shift. I had this with my 93. I put it in neutral and forced it into 4 wheel low. After it went, it is now easier to shift into.
Check the fuses- Shift interlock is the same circuit as brake lights. As a temporary measure - try to turn the key to 1st (unlock) position shift to neutral to start vehicle and then shift to Drive.
The neutral safety switch, release switch, or brake switch is bad.
Push it off a cliff.
That would be a safety feature and is normal.
Check the shifter lock-out on the brake pedal. also check all the fuses.
A couple more suspects...Check the shift interlock fuse - #10(?)Neutral start switch/Transmission Range Sensor?