I've recently updated auto cad LT with the 2017.2 update. (Less than a month ago). One particular drawing refuses to open. I didn't have this problem before the update. A colleague has opened it successfully in their version, and has also created a DXF but it still won't open on my machine. I've tried importing, referencing - but it just refuses to acknowledge it. Even the tab at the top of the page doesn't materialise. The file is unlikely to be corrupt, and is a survey we commissioned. Any help appreciated please...