I would drop the oil, look for any signs of trouble, and check the clutch adjustment as well on her. Couldn't hurt. My 84 200ES when i got it was stiff to shift to a higher gear, pushing down, but going up to a lower gear seemed fine. I did an oil change and checked the clutch adjustment and found the previous owner didn't have it adjusted right, after doing those two things it came back to normal. Maybe i got lucky but thats all i ended up doing.
The 250 is a smidge different and i have heard about that issue that Flossy mentioned, but normally thats not a sudden change. You made it sound like it worked fine the last time you rode it and now suddenly the problem is there? I would go over everything to find what changed. Of course the spring could have broke the first time you went to shift or maybe the last time you put it away but who knows. The neutral light not working is that stupid electrical connector on the neutral switch, its a common problem on the 250. Last one i dealt with i chopped off the connector and soldered the wire right to the terminal on the switch then covered it with heat shrink tubing, fixed it for good!
---------------------------------------------------------
1984 Honda ATC200ES "Big Red"
1982 ATC200E "Hondie"
1988 TRX300FW "Project Quad" Still in progress....