MySQL Bugs: #57856: Object reference not set... when closing model

Bug #57856	Object reference not set... when closing model
Submitted:	29 Oct 2010 22:54	Modified:	30 Nov 2010 1:08
Reporter:	David Olson	Email Updates:
Status:	No Feedback	Impact on me:	None
Category:	MySQL Workbench: Modeling	Severity:	S3 (Non-critical)
Version:	5.2.28 CE	OS:	Windows (window 7 if matters)
Assigned to:		CPU Architecture:	Any

Description:
get an "Object reference not set to an instance of an object" when clicking the X to close a MySQL Model.

I expected the model to close without an error.

after you click ok on the error box, if you try to reopen the model it says it's already open. Likewise if you were to try to close WB it says "do you want to save"  It's like the model didn't finish closing, is still open, and changed, even after we just saved it and closed it, but you can't see anything on the screen still.  The error doesn't occur when saving it though, just when you try to close it.

When you close WB, you get another error: attempt to read or write protected memory.
You have to close WB, ignore the error, and restart WB to open your model again.

How to repeat:

Open model
View ER window
Expand the indexes on a table (click the arrow so they drop down) (I may have clicked the table and got the properties display below too.)
Collapse the indexes
Save model
Close ER window (scorer1)
Close MySQL Model (Scorer2.mwb)
get "Object reference not set to an instance of an object"

Suggested fix:
figure out why closing the model causes a null reference

in the model that causes this I had recently deleted a table, it's relationships, and been editing relationships on other tables. I was wondering if the indexes referred to existing columns still.

screenshots of errors and sequence

Attachment: Close model errors.doc (application/msword, text), 156.50 KiB.

Please try version 5.2.29, Thanks in advance.

No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".