create context to work only with a selected strip

operators/tracker.py

@@ -449,6 +449,10 @@ class VSETB_OT_open_shot_on_tracker(Operator):
 
     @classmethod
     def poll(cls, context):
+        if not context.active_sequence_strip:
+            cls.poll_message_set('No active')
+            return
+
         prefs = get_addon_prefs()
         if prefs.tracker:
             return True