Having the same problem here…
Software version 188.8.131.52
Edit the midi file of a song (the bridge) in reason (same way I did with verse and chorus…)
But once I import it back in the BBM even tho verse and chorus can be edited with no problems, the program crashes when I hit EDIT to make some adjustments…
Fun fact (actually frustrating fact) in 2 occasions, I could open the editing window, but it crashed when I clicked on Quantize (first time) and crashed just 2 seconds after opening it (second time).
P.S. Tho the edit is out of question, I can play the loop normally and use the BBM like always do with this song, I can edit whatever I want, BUT not the bridge.
Also tried creating a new fresh file for the bridge…nothing.
This is the error I get…can’t really understand what that means.
I did the same thing I did with tens of other songs…
Process: BBManager 
Version: 1.6.4 (184.108.40.206)
Code Type: X86-64 (Native)
Parent Process: launchd 
Responsible: BBManager 
User ID: 502
Date/Time: 2017-06-28 23:56:11.080 +0200
OS Version: Mac OS X 10.9.5 (13F1911)
Report Version: 11
Anonymous UUID: A7FA3054-A344-92EA-DF04-831161EF9005
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Application Specific Information:
*** error for object 0x7fc2b89ac690: incorrect checksum for freed object - object was probably modified after being freed.
I’d really appreciate it.
Thank you very much and have a great day.
(I attached the midi file that’s causing troubles…hope it helps)