Empty blocks with explicit minimum tick duration will not be deleted anymore byDelete All Empty Blocks command

engine/main.py

@@ -1039,14 +1039,14 @@ class Data(template.engine.sequencer.Score):
 
         #for trId, track in Track.allTracks.items():
         for track in list(self.hiddenTracks.keys()) + self.tracks:
-            if len(track.blocks) <= 1:
+            if len(track.blocks) <= 1:  #Don't delete the last block in a track
                 continue #next track
 
             #Get all blocks and then remove those with no content.
             trId = id(track)
             listOfBlockIds = track.asListOfBlockIds()
             for block in track.blocks:
-                if not block.data:
+                if not block.data and not block.minimumInTicks: #empty "spacer" blocks with minimum duration will be kept.
                     listOfBlockIds.remove(id(block))
             #Maybe the track was empty. In this case we add one of the blocks again. Otherwise follow up functions will not act.
             if not listOfBlockIds: