Problem with Xampivotgrid software crash

Hello all
I am using XamPivotGrid to summarize my data and visualize the information to build a business analysis application.
I am trying to expand the dimensions related to filters, but I get the error' Object reference not set to an instance of an object”if the dimension related to that filter is not expanded.
The screenshot of the error is as follows:

BMS – GP – 2012
Object reference is not set to an instance of an object.
OK
I can't get to the root cause of the problem. can anyone please tell me what is the event fired at that time?
Please help me in fixing the issue. Any kind of help will be highly appreciated.
Waiting for your replies
Kind regards
Grace
