I'm curios why the print does this? The weak spot is at the top of the print. This happened before and thought it was a fluke but then it happened again so I'm wondering why it might be happening. Help is greatly appreciated.
Firstly.....your image is not showing, so its impossible to see what your issue is.
Having said that, may I take a punt in the dark as to a suggested solution.....
On the Mesh dropdown menu is an option "Separate Connected Surfaces". Click that option. If your model list now has more entries that it had before.....then my guess is probably right, and your model will slice.
If not, please have another go at attaching your screenshot...try using the Attachments button at the bottom of the "post" page rather than including a link to a photo site that in this case prohibits using the link on other sites such as forums.