Stuck in 2nd gear.

As the title says.
All linkage etc doing as it should but can't get it to change gear in any direction.
Fitted a new slipper clutch recently. Put the bike in gear to remove the clutch nut and it worked fine then. The clutch is working fine.
I've tried starting the bike and letting it run but this didn't make any difference.
Open to any suggestions.
Ps it's a track bike with race shift and after market rearsets.

 

Butterfly spring has popped off the selector shaft by the sound of it mate

 

Does that involve a strip down?

 

Problem solved.
When clutch was removed the spring was in the position in the first pic.
The second pic is how it should be.

 

Problem solved.
When clutch was removed the spring was in the position in the first pic.
The second pic is how it should be. View attachment 48164 View attachment 48165