Check for compatible beat type

template/engine/duration.py

@@ -124,6 +124,8 @@ def jackBBTicksToDuration(beatTypeAsTraditionalNumber:int, jackTicks:int, jackBe
     if None in (beatTypeAsTraditionalNumber, jackTicks, jackBeatTicks):
         return None
     else:
+        if not beatTypeAsTraditionalNumber in traditionalNumberToBaseDuration:
+            raise ValueError(f"{beatTypeAsTraditionalNumber} must be one of {traditionalNumberToBaseDuration}")
         beatTypeDuration = traditionalNumberToBaseDuration[beatTypeAsTraditionalNumber]
         #print (beatTypeAsTraditionalNumber, beatTypeDuration, jackTicks, jackBeatTicks)
         factor = beatTypeDuration / jackBeatTicks