RaceOnRCWCleanup was detected

Question

Recently, I faced New Problem,

 

Error Text is - 

RaceOnRCWCleanup was detected

Message: An attempt has been made to free an RCW that is in use. The RCW is in use on the active thread or another thread. Attempting to free an in-use RCW can cause corruption or data loss.

 

I have too big for loop inside of BackgroundWorker,

Click on link to see screenshot,

http://s12.postimg.org/cobr8nn25/RCWerror_Copy.png 

 

 

thanks,