Crash when reseting slurs position after toggle copy-paste in parts and main score

2.1 version / Windows7

1) "Untitled" score
2) Enter eg four quarter notes with two slurs in first measure
3) Generate parts -> New all -> Ok

• The test file at this step: slurs parts test.mscz

4) Copy-paste the measure (main score) in the piano part
5) Copy-paste the measure (piano part) in main score
6) Detach two slurs - but only one is sufficient - with the mouse, which were overlapping (image below)

7) Select the measure
8) Ctrl + R

Result: crash

• Note: same result by permuting steps #4 and 5. You get the same crash in part after after completing the other steps. The main point, so: a round trip of copy-paste between main score/parts (or the reverse) is required.