Good Afternoon,

I am trying to create a vb.net program that acts as an addin to solidworks.  What this program does is draw some things on a 2D Drawing, and gets some values from the drawing.  All this is done successfully.  Then, the interaction with the solidworks drawing is complete and the program proceeds onto the next screen. 

When I finish the interaction with solidworks, i use:

System.Runtime.InteropServices.

Then I open up a new form in vb.net to do some processing with this data.  However, sometimes this crashes solidworks.  Solidworks will crash and then I get the error

The thread tried to read from or write to a virtual address for which it does not have the appropriate access

It seems that any runtime error in vb.net will crash solidworks.  The error I get sometimes with 

System.Runtime.InteropServices.Marshal.ReleaseComObject(userAddin)



is The object's type must be __ComObject or derived from __ComObject.  It seems approximately 1/10 times I will get this error, which is probably why solidworks is crashing.  Any advice on how to dispose the connection to solidworks to proceed with further processing?



Thank you!