it has been awhile since I received a similar error, so I had to do a little bit of research. The general consensus is that the error is given when attempting to access a pointer that has either not been properly initialized, or has been deleted. Essentially trying to de-reference a dangling pointer that may point to an unexpected area in memory. If my explanation proves to be insufficient, i'll attempt to clarify, or through a google search you will be able to procure a wealth of info in regards to this particular error.
Might also be helpful to post the source file(s) that is generating the errors.