AutoCAD Message unable to save to drawing

Hello,
Is not the first time when I want to save .dwg file. It doesn’t matter that is a small file or a big one the error is the same. Can anyone help me to fix this ? What could be the problem ?
Thank you experts !

AutoCAD Message
Unable to save to drawing C:UserslgorDocumentslgorDesignKazenny
PereulokKazenny_new.dwg.
Drawing saved to C:UserslgorDocumentsIgorDesignKazennypreuloksav81EB.tmp
OK
