Here’s a tip on how to stop a never ending (looping) Midi track in Realband.
It was supplied to me by LynB and thought it might help others with the same problem.

Open the Classic Tracks Window and look at the column on the right titled "Loop".
The entry here should be zero if not, then the track will loop by the number of times shown in the track.
There is a long term minor bug in RealBand whereby if you "Remove" a track, then a new track number 48 is added to the end of the track list with a 1 in the Loop Column.

After a while it is necessary to Zero all the unwanted numbers to obviate any problems should Midi data be transferred to one of the tracks as the loop number is not automatically overwritten.

Check also the Bars Window and see whether the bar content for the track extends past all the others. Delete the bars not required.