After upgrading from 2012 to 2014 I have this saving problem with certain drawings. I get the "unable to save drawing ..." error, resulting in saving to a tmp file, then I qsave again and it works. It only seems to work for some drawings, and curiously, they are the same types of drawings, although in different folders. They are drawings that have two or three xrefs overlaid, but several copies of each xref in various rotations, if that matters. Also interesting is that I have other drawings that are much larger in size, and with xref's attached, but they don't exhibit any saving problem.
I have tried auditing and recovering these drawings, but to no avail. I suspect it's a timing problem during the save process, but if so, I can't determine if it's a Windows 7 problem, an Autocad 2014 problem, or a hard-drive problem. Any ideas?
I get the same error in 2012. As long as I am able to save on the second try, I don't sweat it. I always thought it was a server hiccup. As in, I was trying to save at a time when the dwg autosave might have been doing a save.
I am getting the same error message, having recently upgraded to 2015, I can't say i ever had this error in any previous versions.