Can' edit Midi track

[Clint Swank]

I moved a track from an earlier version of a song. The track plays, but in piano roll view it's uneditable. No editing tools (select, move, etc) respond. To see if the importation process was involved, I opened several earlier versions of the song and discovered the same problem. No other tracks in any version suffer from it. Checked "freeze" and "lock", nada. Ideas?

[reginaldStjohn]

I don't know but some things to try. Bounce the midi clip. drag it out to the browser or explorer and then drag it back in?

[Promidi]

The MIDI track would not be a step edited track by any chance, would it? 

Right click on the clip.  If the View > Step edit is NOT greyed out, then it's a step edited clip.

Check the clip corners.  Are they slightly rounded?

If you bounce the clip, does it then become edible?